METALLURGICAL A B S T R A C T S
(G E N E R A L A N D N O N -F E R R O U S )
Volume 2 D E C E M B E R 1935 P a rt 12
I.— PR O PE R TIES OF METALS
( C o n tin n e d f ro m p p . 4 9 7 -5 0 2 .)
»The Diffusion of Gases Through Metals, ü . —Diffusion of Hydrogen Through Aluminium. C. J . Smithells an d C. E . R ansley (Proc. Roy. Soc., 1935, [A], 152, 706-713).—H ydrogen is found to diffuse a t a m easurable ra te through aluminium a t tem peratures above 400° C. The ra te of diffusion depends on the state of the su rface; it is greatest for a surface freshly scraped in hydrogen, but it decreases rapidly, an d a fte r some hours reaches'a steady value which is about of the in itia l rate. This decrease is a ttrib u te d to contamination of the surface by oxygen. The effect o f tem perature (T ) and pressure (P ) on the rate of diffusion (D) are represented by D = KPle~l>lT.
The value of 6 for a freshly scraped surface is 15,600, and for an anodically oxidized surface about 21,500; K varies from 3-3 to 0-42 for different states of the surface.—J . S. G. T.
*The Solubility of Hydrogen in Molten Aluminium . L. L. Bircum shaw (Trans. Faraday Soc., 1935, 31, 1439-1443).—The solubility of hydrogen in aluminium is a t 700° C. 0-23, a t 800° C. 0-89, a t 9003 C. 1-87, and a t 1000° C.
3-86 c.c. (N.T.P.) per 100 grm. of m etal, an d th e “ sa tu ra te d ” heat of solution 43,400 gnn.-caL/grm.-mol. o f dissolved gas. The solubility values agree closely with those of Röntgen an d B raun (Met. Abs. (J. In st. Metals), 1932, 50, 721).—A. R . P.
*Study of the Phenomena of Plastic Deformation in Single Crystals of Aluminium under Tension. A. Elnikow (Zhurnal eksperimentalnoy i teore- ticheslcoy F iziki (J. Exper. and Theoret. Physics), 1934, 4, 100-115).— [In Russian.] Pole diagram s of L aue spots of single crystals o f alum inium deformed by tension show th a t during slip an axis of ro tatio n of the crystal elements is formed in th e plane o f slip an d perpendicular to th e direction of slip. The angle of ro tatio n is 5-5°-6-5° w ith a deform ation of 18-20% . I t is shown th a t the thickness of th e b en t layer is less th a n 0-17 mm ., w ith a length of unit of slip of 1-2 mm. A ccurate analysis of the diagram s indicates that there is also a subsidiary axis o f ro tatio n a t rig h t angles to the m ain axis and in the same plane. F rom the theory of elasticity th e appearance o f this axis indicates an elastic bending o f th e slip-planes an d enables a value to be calculated for Poisson’s coefficient. The shape of th e bent surfaces has been determined m athem atically.—X. A.
*The Nature of the Phenomena of “ Rest ” and Recrystallization in Single Crystals of Aluminium. X. J . Seljakov and E . I. Sovz (Dokladi Akadem ii Nauk (Rep. Acad. Sei. U .S .S .R.), 1935, 2, 125-133).— [In R ussian and G er
man.] Düring recovery in alum inium single crystals noticeable changes occur in the distribution of in ten sity o f certain spots (accom panied by a n increase in their sharpness) on X -ray plates ta k e n a t large angles. D uring recry stal
lization the position of th e new crystals differs from th a t a fte r deform ation.
After hot-deformation th e lines are sharper th a n a fte r cold-deform ation.
The recrystallization and deform ation tex tu res of polycrvstalline alu m in iu m are identical.—X. A.
* Denotes a paper describing th e results of original research.
+ Denotes a first-class critical review.
554 Metallurgical Abstracts
Vo l. 2*On the Recrystallization oi Pure Aluminium. J . C alvet, J . T n lla t, and M.
P aic (Light Metals Research, 1935, 4, 94-95).—T ran slated from Compt. rend., 1935, 201, 426—428. See M et. Abs., th is vol., pp. 453-454.—J . C. t .
♦The Photoelectric Effect of Aluminium Films Deposited by the Vacuum Evaporating Process. E . Gaviola an d Jo h n Strong (R h ys. Rev., 1935, [ii], 48, 483). A b stract of a p aper read before th e A m erican P hysical Society. The effect has been studied using a carefully cleaned an d p artially outgassed glass cell provided w ith a q u artz window an d a charcoal-liquid air tra p . The cell has th e shape of a horn, so th a t absorption of th e oncoming radiation is practically to tal. As light source a m ercury lam p was used. The light was resolved by a H ilger q u artz m onochrom ator. I t was found th a t th e long wave
length lim it of th e sensitivity curve lies betw een 2800 an d 2900 A., an d th a t it has a definite selective m axim um ab o u t 2700 A.—S. G.
♦Researches to Convert Antimony into the Glassy Amorphous State. G.
T am m ann an d W . M uller (Z . anorg. Chem., 1934, 221, 109—112). When antim ony is m elted w ith a sm all q u a n tity of an tim ony selenide an d allowed to fall in sm all drops of ab o u t 0-4 mm . diam eter in to liquid a ir a t — 180° C., particles of glassy am orphous an tim o n y are obtained w hich can be caused to crystallize by heating a t 520° C. for 30 m inutes. Since these effects are not obtainable w ith pure antim o n y i t is assum ed th a t th e a d d itio n of selenium re ta rd s th e ra te of crystallization sufficiently to re ta in th e am orphous state a fte r severe quenching.—A. R . P.
♦Studies on Explosive Antimony. II.—Its Structure, Electrical Conductivity, and Rate of Crystallization. C. C. Coffin (Proc. Roy. Soc., 1935, [A], 152, 47-63).—Continuing previous w ork (Met. Abs., 1934,1, 477), C. has shown th a t th e explosive electrolytic deposit of antim ony possesses a heterogeneous gel
like stru ctu re in w hich one phase is oriented parallel to th e lines of th e depositing current. T his oriented phase is regarded as an SbCl3-S b complex due to the deposition of a complex ion. The o th er phase is p robably am orphous a n ti
m ony. I n th e case of fresh deposits, th e specific resistance, p, which is about 105 tim es th a t of ordinary antim ony, a n d w hich h as a negative exponential tem p eratu re coeff., is given b y log p = (8-7 X 102)/2' + 0-0956' — 3-26, where T is th e tem p eratu re (° C.) an d C th e % o f SbCl3 in th e m etal. This equation is n o t valid for p a rtia lly crystallized deposits. The conduction is probably m etallic in ch aracter, O hm ’s law being obeyed an d F a ra d a y ’s law not involved. B etw een 55° an d 100° C. am orphous an tim o n y crystallizes a t a m easurable ra te w hich is independent o f th e am o u n t of sa lt in th e m etal, and w hich can be represented by th e eq u atio n referring to a firs ..-order reaction.
The A rrhenius equation applies an d gives a n energy of activ atio n of 27,300 cal./grm . atom . The ra te of crystallization a t T ° C. is given b y th e equation log k = 31-40 ± 27,300/R T .—J . S. G. T.
Molecular Arrangement of Amorphous Antimony. J . A. P rin s (Chem.
Weekblad, 1935, 32, 348-349; Brit. Chem. A bs., 1935, [A], 919).—See also Met.
Abs., th is vol., p. 454. A m orphous (“ explosive ” ) an tim o n y prepared by electrolysis of SbCl3 contains occluded SbCl3, w hich keeps th e m etal in a
“ dispersed ” form. I t can be produced in th in layers by d istillatio n in a high vacuum , b u t th ick layers crystallize im m ediately. The electron diffraction p a tte rn corresponds w ith a n atom ic arrangem ent sim ilar to t h a t in crystalline antim ony, of co-ordination num ber 6.—S. G.
♦The Size and Arrangement of Bismuth Microcrystals Formed from Vapour.
C. T. Lane (R hys. Rev., 1935, [ii], 48, 193-198).—See M et. Abs., th is vol., p. 365.—J . S. G. T.
♦The Electrical Resistance of Cadmium, Thallium, and Tin at Low Tempera
tures. W. J . de H aas, J . de Boer, and G. J . v an der Berg (Physica, 1935, 2,453- 459; an d Comm. K . Onnes Lab. Leiden, No. 236d, 1935).— [In E nglish.] The
“ ideal resistance curves of cadm ium an d tin (calculated b y m eans of M atthie-
1935
I . — Properties o f Metals 555
sen’s rule) show a dependence respectively on ab o u t T 13 and T*, where T is the absolute tem perature. The “ ideal ” resistance curve of thallium is not to be represented by one single power of tem perature, because of tbe faint S-form of the curve on the logarithm ic scale.—S. G.
♦A Revision of the Atomic Weight of Cæsium. Gregory P au l B axter and Joseph Smith Thomas (J. Amer. Chem. Soc., 1934, 56, 1108-1110).—By com
parison of pure cæsium chloride w ith silver th e atom ic w eight of cæsium was found to be 132-91.—L. A. 0 .
♦Investigations Relating to Allotropy Exhibited by Very Pure Calcium.
Alfred Schulze (Physikal. Z ., 1935, 36, 595-598).—In continuation of p re
vious work (Met. Abs., 1934, 1, 65), S. establishes, by determ inations of cooling curves, m easurem ents of electrical resistance, and of expansion, the definite existence of allotropie transform ations of calcium a t about 300° C.
(ccj8), and a t about 450° C. (j3y). The transform ation tem perature (/3y) a p parently increases w ith increasing p u rity of th e m etal, which in the present case was 99-9%.—J . S. G. T.
♦Chemical Preparation of Cerium and Its Alloys. A. K a rl (Bull. Soc. chim.
France, 1934, [v], 1, 871-877 ; G. Abs., 1935, 29, 92).—A fter failing to obtain cerium in the electric furnace by reaction betw een eerie oxide and silicon ca r
bide, K. succeeded in preparing cerium of 97-05% p u rity an d some if its alloys by reducing cerous chloride w ith comm ercial calcium according to 2CeCl3 + 3Ca — >- 3CaCl2 + 2Ce. The preparation of ferro-cerium offers no difficulties.
The required q u an tity of iron can be added before or a fte r th e reaction w ith calcium. A typical analysis shows cerium 63-4, iron 35-85, copper 0-98, cal
cium 0-33, and magnesium 0-16%. The m ethod and equipm ent finally adopted for preparing cerium and its alloys as well as the various m ethods for m aking cerous chloride are discussed.—S. G.
♦A New Revision of the Atomic Weight of Chromium. II.— The Ratios of Cr02Cl2 : 2Ag and Cr02Cl2 : 2AgCl. F . Gonzalez Nunez (Anales soc. esp a h .fis.
guim., 1935, 33, 533-548; C. Abs., 1935, 29, 6807).—A value o f 52-013 ± 0-001 was found for th e atom ic w eight of chrom ium .—S. G.
♦Solubility of Oxygen in Solid Cobalt and the Upper Transformation Point of the Metal. A. U. Seybolt and C. H . M athewson (Metals Technology, 1935, 2, (Sept.); A .I.M .M .E . Tech. Publ. No. 642,1-17).—F rom analysis and m icro
graphie exam ination of specimens of cobalt soaked in a ir or oxygen for some days a t 600°-1500° C., it is concluded th a t th e solid solubility of oxygen (as cobalt oxide) in cobalt increases from ab o u t 0-004% a t 550° C. to 0-020% a t 875° C., a t which tem perature the hexagonal form of cobalt changes into th e cubic face-centred form. This transform ation occurs a t ab o u t 850° C. in th e oxygen-free m etal, b u t is a v ery sluggish reaction. The solubility of oxygen in the cubic form of cobalt is 0-004% a t 875° C. an d increases alm ost linearly to 0-022% a t 1450° C.—A. R . P.
Change of Resistance of Cobalt in Longitudinal Magnetic Fields. M. S.
Alam (Current Sci., 1934, 3, 155-156; B rit. Chem. Abs., 1935, [A], 18).—See also Met. Abs., this vol., p. 414. C ontrary to McCorkle (Phys. Rev., 1923, [ii], 22, 271) the resistance of cobalt increases to a satu ratio n value a t 1200-1300 gauss in longitudinal fields. H ysteresis also occurs.—S. G.
♦The Conductivity of Copper Castings. L yall Zickrick (Gen. Elect. Rev., 1934, 3 7 ,187-190).—R ead before th e A m erican In s titu te of Mining an d M etallurgical Engineers. The sp. gr. an d conductivity of copper deoxidized w ith silicon, calcium, boron carbide, calcium boride, an d silico-m anganese boride were determined for castings in sand and grap h ite moulds an d before an d a fter cold-working and annealing. Good density an d conductivity figures are obtained only by using clean, pure copper w ith th e m inim um oxygen content and by regulating th e am ount of deoxidizer added so th a t th e m inim um excess remains in the casting. E lem ents which have a high affinity for oxygen and
556 Metallurgical Abstracts
Vo l. 2are insoluble or only slightly soluble in copper have th e least effect on the electrical co n d u ctiv ity ; care should be ta k e n th a t th e s u r f a c e o f t h e mo ten m etal is protected from access to air by a suitable cover since th e m etal rapidly absorbs oxygen. Calcium boride, calcium, an d boron carbide are th e most satisfactory deoxidizers.—A. R . P .
*A Quantum Mechanical Investigation of the Cohesive Forces of Metallic Copper. K . Fuchs (Proc. Roy. Soc., 1935, [A], 151, 585 602). The binding energy in copper is calculated and found to be of the rig h t order of m agnitude, b u t a correction—which is deduced by a sta tistic a l m ethod is necessary to obtain th e correct com pressibility. The reason for th e face-centred structure of copper is discussed; th is stru c tu re for copper has a low er value of energy th a n th e body-centred s tru c tu r e ; for sodium b o th stru ctu res have alm ost equal energies.—J . S. G. T.
* Apparatus for Grinding Copper in a High Vacuum and Adsorption of Gases by the Powder Obtained. F. D urau an d H . F ran ssen (Z. P hysik, 1934, 89, 757-773; C. Abs., 1935, 29, 20).—A discussion of th e problem w hether gases adsorbed by m etal powders will s ta y a t th e surface an d can be rem oved by mere evacuation. Copper pow der is ground in high vacuum w ith a specially- designed apparatus. F rom th e am o u n t of nitrogen, hydrogen, ethane, ethyl
ene, an d carbon monoxide adsorbed a t room tem p eratu re no measurable qu an tities are retained in a vacuum , while oxygen an d carbon dioxide are more persistent.—S. G.
^Diffusion of Positive Ions of Salts Through Copper, Silver, and Gold at High Temperature. Analysis of the Ions Emitted with the Aid of a Mass Spectro
graph. Je a n Cichocki (A nn. Physique, 1933, 20, 478-518; C. Abs., 1934, 28, 1920).—Cf. M et. Abs. (J. In st. Metals), 1933, 53, 66. Folded sheets of copper, silver, or gold containing various salts em it a t high tem p eratu re simple metal ions of the salt an d sm aller am ounts of com plex ions of th e sheet m etal. The tim e for m axim um emission a t c o n sta n t tem p eratu re is proportional to the thickness of th e sheet, a n indication of diffusion th ro u g h th e m etal. A n energy loss shown by th e ions was explained b y a hypothesis of large ion emission.
—S. G.
*On the Change of the Resistance of Single Crystals of Gallium in a Magnetic Field.—n i . W . J . de H aas an d J . W . Blom (Physica, 1935, 2, 952-958; and Comm. K . Onnes Lab. Leiden, No. 237d, 1935),— [In English.] See also Met.
Abs., 1934,1, 285, 546. The change of th e resistance of single crystals of pure gallium (which had the pseudo-tetragonal axis parallel to th e length of the wire) in a m agnetic field perpendicular to th e wire was m easured a t liquid helium tem peratures. A t 4-22° K . th e increase of th e resistance is larger th a n at liquid hydrogen tem peratures. A t 4-22° K . a n d 1-35° K . th e increase is nearly th e same. The separation of th e secondary m axim a a n d m inim a in th e ro tatio n al diagram s is larger a t liquid helium tem p eratu res.—S. G.
*Purification of Gallium by Fractional Crystallization of the Metal. Jam es I.
H offm an an d B ourdon F . Scribner (J . Research N at. B ur. Stand., 1935, 15, 205-209; an d Research Paper, No. 823).— I t is shown in th is paper th a t if gallium , containing (as im purities) sm all am ounts of antim ony, bismuth, chrom ium , cobalt, colum bium , copper, gold, indium , iron, lead, manganese, m ercury, m olybdenum , nickel, osmium , palladium , p latin u m , rhodium , ruthenium , silver, thallium , tin , v anadium , an d zinc, is su b jected to fractional crystallization of th e m etal, all th e im purities nam ed te n d to concentrate in the crystalline portion, w ith th e following exceptions : silver, m ercury, indium, lead, and tin are concentrated in th e m olten resid u e; copper an d thallium rem ain ab o u t equally divided betw een crystals an d resid u e; zinc is dissolved b y th e hydrochloric acid und er w hich th e crystallization tak es place, and is entirely elim inated. I t is also shown th a t separation from iron or platinum
1935
I . — Properties o f Metals 557
in excess of 0-001%, from indium or lead in excess of 0-01%, or from tin in excess of 0-02%, by fractional crystallization of th e m etal is im practicable.
—S. G.
♦Atomic Weight oi Gallium. G. E. F . Lundell and Jam es I. Hoffman (J . Research Nat. Bur. Stand., 1935, 15, 409-420 ; and Research Paper No. 838).
In this determination, weighed portions of the pure m etal were converted to the hydroxide, the sulphate, and th e n itrate, respectively. These were then heated until they were changed to th e oxide, G a20 3, which was finally ignited at 1200°-1300° C. By this procedure the atom ic w eight is related directly to th at of oxygen. Prelim inary tests showed th a t the m etal was free from an appreciable film of oxide and did n o t contain occluded gases. The highly ignited oxide, obtained through th e hydroxide or the sulphate, contained no gases and was not appreciably hygroscopic. The oxide obtained by igniting the nitrate was less satisfactory. To m ake possible th e correction of the weights to the vacuum standard, the density of th e oxide was also determ ined and found to be 5-9s grm ./cm .3. The value for th e atom ic w eight based on th is w ork is 69-74.—S. G.
♦Thermal Effects Produced by the Exposure of Massive Gold to Saturated Water Vapour. Frederick B arry and E llio tt Pierce B a rre tt (J. Amer. Chem.
Soc., 1933, 55, 3088-3098).—L. A. O.
♦A Note on the Heat of Sorption of Water Vapour hy Massive Gold. E llio tt Pierce B arrett (J. Amer. Chem. Soc., 1933, 55, 4006—4009).—See also preceding abstract.—L. A. 0 .
♦A Revision of the Atomic Weight of Lanthanum. I.— The Analysis of Lanthanum Bromide. II.— The Specific Gravities of Lanthanum Chloride and Bromide. IH.—The Increased Efficiency of Calcium Bromide as a Drying Agent at Low Temperatures. Gregory P au l B ax ter an d E velyn E m m a Behrens (J. Amer. Chem. Soc., 1932, 54, 591-601).—A value of 138-92 is found for the atomic weight of lanthanum .—L. A. O.
♦The Atomic Weight of Uranium Lead from Great Bear Lake, N.W.T., Canada, Pitchblende. Jo h n P u tn am M arble (J. Amer. Chem. Soc., 1934, 56, 854-856).—The atom ic weight of lead ex tracted from G reat B ear Lake, N. W .T., Canada, pitchblende is 206-054. This figure is slightly lower th a n the “ m ean mass-number ” calculated from A ston’s observations on identical m aterial.
I t is in accord w ith a value of approxim ately 206 for “ pure ” uranium lead, if Pb208 reported in the sample is derived from “ common ” lead.—L. A. O.
♦Photoelectric Properties of Pure and Gas-Contaminated Magnesium. R . J . Cashman and W. S. H uxford (Phys. Rev., 1935, [ii], 48, 475).—A b stract of a paper read before the A m erican Physical Society. Specially purified samples of metallic magnesium were freed from gas by successive distillations an d very slow sublimation in a high vacuum . The photoelectric threshold was found to he a t 3430 fi; 20 A., both for layers deposited on m olybdenum an d ta n ta lu m plates and for those deposited on the glass walls of th e tube. A threshold characteristic of hydrogen-contam inated surfaces lies a t 5100 A. M inute amounts of oxygen sensitize pure m agnesium , causing a shift in th e threshold to about 6000 A. F u rth er exposure of this sensitized surface to sm all am ounts of oxygen results in deactivation, an d a recession of the threshold to a value below 2000 A. Air and hydrogen, or m ixtures of oxygen an d hydrogen, cause a marked increase in emission, w ith excursions of th e long w ave-lim it to 7000 A. and beyond. Magnesium surfaces are sensitized by nitrogen only when a glow discharge is set up in the gas. These changes in w ork-function are explained on the hypothesis th a t surface films of polar non-hom onuclear mole
cules are formed by the action of the various gases. Fow ler’s theory is found to hold accurately for m agnesium surfaces activ ated by hydrogen, th e a p p aren t threshold a t 5100 A. being changed to th e tru e value 5040 A.—S. G.
558 M etallurgical Abstracts
Vo l. 2tOn the Production and Properties of Pure Manganese. S. A. Pogodin (M etallurg (M etallurgist), 1935, (2), 101-110).— [In R ussian.] A review o f the lite ra tu re .—N . A.
*The Principal Expansion Coefficients of Single Crystals of Mercury.
D onald M. H ill (P h ys. Rev., 1935, [ii], 48, 620-624).— The expansion coeffs.
(a) were m easured a t 5° in terv als from — 115° to — 160° C. an d m ean values d eterm ined from — 160° to — 190° C. T he u pper lim it of th e m easurem ents was set b y a recrystallization process w hich set in betw een — 115° an d
— 110° C. oc) | was found to be larger an d to increase m ore rap id ly w ith te m p e ra tu re th a n ax- The relatio n betw een expansion an d tem p eratu re is n o t lin ear as found by C arpenter an d Oakley {Met. Abs. (J. In st. M etals), 1931, 47, 468). Several crystals h a d lower specific resistances th a n th e values o f pn given b y G riineisen an d Sckell (M et. A bs., 1934, 1, 547).—J . S. G. T.
♦Anchoring the Mercury Pool Cathode Spot. Lewi Tonks (Physics, 1935, 6, 294-303).— C ertain m etals projecting th ro u g h a m ercury cathode are know n to
“ anchor ” th e cathode sp o t an d p rev en t i t w andering over th e cathode. T his p ro p e rty is found to characterize iron, palladium , zirconium , p latin u m , chrom ium , colum bium , iridium , m olybdenum , ta n ta lu m , tu n g sten , an d depends on w ettin g o f th e m etal b y th e m ercury, an d th is again depends on th e m etal surface being clean.—J . S. G. T.
♦The Atomic Heat of Nickel from 1 1 ° to 19 0° K. W . H. K eesom an d C. W . C lark (Physica, 1935, 2, 513-520; also Comm. K . Onnes Lab. Leiden, No.
235e, 1935; an d (ab stract) Proc. K . A kad. Wet. Amsterdam , 1935, 38, 490- 491).— [In E nglish.] T he atom ic h e a t o f nickel was m easured from 1-1° to 19 0° K . The atom ic h e a t surpasses largely th e h e a t cap acity due to the atom ic lattice, calculated from D ebye’s T 3 law w ith 0 = 413. The additional h e a t cap acity for th e range T l°-9 -0 ° K . can be represented, how ever, by C = 0-001744T . I t follows a n o th er law an d considerably surpasses th e co n tri
b u tio n th a t will be due to th e in teractio n energy o f th e electrons th a t are responsible for ferrom agnetism . The hypothesis is p u t forw ard th a t it is connected w ith th e energy of th e conduction electrons. The fa c t th a t it is m an y tim es larger th a n follows from Som m erfeld’s form ula for free electrons th e n shows t h a t in th e corresponding energy b an d , a t least a t th e level o f the lim iting energy, th e d ensity of th e possible energy sta te s is p articu larly large.
—S. G.
♦On the Validity of Becker’s Relation for the Initial Permeability of Highly- Drawn Nickel Wire. G e rtru d Scharfi (Z. P hysik, 1935, 97, 73-82).— Becker’s relatio n is expressed b y th e equations n a = J J H = Jcc 3)3 \KZ , where n a is th e in itia l perm eability in a w eak field of stre n g th H , J 0 is th e corresponding m agnetic m om ent p er cm .3 of th e w ire, Loo corresponds to m agnetic sa tu ra tio n a t th e ap p ro p riate tem p eratu re, Z th e tension in th e d irection of H (parallel to th e axis o f th e wire), a n d hR is th e longitudinal sa tu ra tio n m agnetostriction (Z. Physilc, 1931, 71, 553). T his relatio n has been established a t room te m p eratu res b y K ersten . I t is now established th a t a t tem p eratu res u p to th e Curie p o in t in th e case o f a nickel w ire u n d er tension : (1) th e in itia l m agnetiza
tio n curve is linear in th e case of large tensions, e.g. from 6-9 to 18 k g./m m .2;
(2) th e in itia l perm eability is pro p o rtio n al to 1 ¡Z a n d (3) th e value o f 3n 0Z agrees w ith th e experim ental value of Jcc 2/>.x . B ecker’s relatio n is th u s found to be obeyed.— J . S. G. T.
♦Magnetic Properties of Nickel in the Neighbourhood of the Curie Point.
L. N6el (J. P hys. R adium , 1935, [vii], 6, 27-34).—A p p aratu s for th e accurate m easurem ent o f m agnetic susceptibilities (yr) in fields of stren g th s 50-1000 o ersted ts a t tem p eratu res betw een th e Curie p o in t (358° C.) an d 368° C.
(correct to w ithin i 0-3°) is briefly described. The value of 1 /y is found to v a ry in a reg u lar m an n er w ith th e tem p eratu re ( T ); th e sam e is tru e o f th e first derivative o f 1 /y w ith resp ect to T . The m agnetic characteristics shown
1935
/ . — Properties o f Metals 559
by th e 2 specimens of nickel exam ined in the im m ediate neighbourhood of the Curie point indicate a certain “ spread ” (étalement) of th e Curie point of the order of 1°, which is greater th e less pure the nickel. The values of «( 1 lyj¡citL- expressed as a function of T agree w ith the results due to W eiss and F o rrer and confirm th e value of 1 B ohr m agneton a ttrib u te d to th e elem entary carrier ot th e m agnetism of nickel. The value of d T jd (\jyf) a t th e Curie p o in t is equal to 71-3.—J . S. G. T.
♦The Negative Matteucci Efiect. E . E n g lert (Z. P hysik, 1935, 97, 83-93).—
Becker’s theory of m agnetization of m aterials under tension is extended to the case o f nickel wires u nder torsion. The negative M atteucci effect (see Oster- m ann an d v. Schmoller, Z . P hysik, 1932, 78, 690; 1935, 93, 35) exhibited by a tw isted nickel wire an d by a wire composed of iron 92, nickel 8% , an d b y a nickel tu b e is found to be in approxim ate q u a n tita tiv e agreem ent w ith th e
theory.—J . S. G. T. .
♦The Gyromagnetic Effect of a Ferromagnetic Substance above Its Curie Point. W. Sucksm ith (H elv. Phys. Acta, 1935, 8, 205-210; C. Abs., 1935, 29, 6809).—The m agnetic m om ent of th e nickel ato m in m etallic nickel differs below an d above th e Curie p o in t (0-6 and 1-6 B ohr m agnetons, respectively).
The m easurem ent of th e gyrom agnetic effect below th e Curie p o in t shows th a t th e m agnetism of th e nickel atom arises from electron spin. There is no con
trib u tio n from th e o rb ital m om ent, since to a good approxim ation th e L andé g factor is found to have th e value 2-0. M easurem ents show th a t in th e p a ra m agnetic sta te , above th e Curie point, nickel atom s also display p u re spin m agnetism . The g factor was determ ined for ferrom agnetic nickel-copper alloy above th e Curie point. I n th is alloy th e nickel atom has th e same m agnetism as in pure nickel, an d th e value found g = 2 for th e param agnetic sta te excludes an y effect o f th e o rb ital m om ent.—S. G.
♦Diffusion of Deuterium in Metals [Palladium]. T. E ranzini (A tti B . Acad.
Lincei (Roma), 1935, 21, 577-580; Sci. Abs., 1935, [A], 38, 790).—See also M et. Abs., th is vol., p. 203. Since i t is know n th a t hydrogen is readily occluded by palladium , th is m etal is used in a n a tte m p t to discover i f deuterium also diffuses th ro u g h m etals. The experim ent, w hich depends for solution on spectroscopy an d m icro-photom etry, again shows th a t occluded hydrogen is displaced by a n electric field, b u t gives no su p p o rt to a n analogous effect for
deuterium .—S. G. i
The Absorption of Gases by Liquids and Solids, with Particular Reference to Hydrogen and Palladium. E. J . T rom p an d B. de Loor ( J . Chem. M et. M in . Soc., S . A frica, 1934, 35,169-181).—A theoretical physico-chem ical discussion.
—A. R . P .
* Adsorption of Hydrogen by Palladium in Presence and Absence of Water.
M I T em kin an d A. N. B akh (J. Phys. Chim. Ü .8 .S .R ., 1934, 5, 809-811 ; B rit.
Chem. Abs., 1935, [A], 1068).— [In R ussian.] N eith er w ater nor oxygen has a n y effect on th e ra te or am o u n t of hydrogen adsorbed b y palladium or p a lla dium black a t 15°-20° C. The to ta l adsorption is 67-5 c.c. per grm .—S. G.
*Diffusion of Hydrogen in Palladium. B. D uhm (Z. P hysik, 1935, 94, 434 436).—I t is show n experim entally th a t for hydrogen concentrations betw een 0 an d 30 an d betw een 800 an d 1000 volum es of th e m etal, solution phases of hydrogen an d palladium are present in w hich unhindered diffusion of th e gas can occur. The diffusion coeff. (D) is th e sam e w ithin b o th ranges an d is equal to 9-6 X 10‘5 cm .2/second. The effective charge o f th e pro to n s in palladium is found to be a sm all fraction o f th e elem entary charge; th is is a ttrib u te d to screening b y a sw arm of electrons.—J . S. G. T. _
♦Different Forms of Hydrogen. An Attempt to Separate Them by Diffusion Through Palladium. V ictor L om bard an d Charles E ichner (J . Chim. physique, 1934, 31, 396-406).—L. an d E . refer to experim ents u n d ertak en b y th em in 1929-1930 w hereby allotropie modifications of hydrogen (ap p aren tly heavy an d ord in ary hydrogen) were sep arated b y diffusion th ro u g h palladium .—J . T .
560 Metallurgical Abstracts
Vo l. 2♦Permeability of Palladium to Hydrogen. V.—New Researches on the Influence of Temperature. Tests with Pure and Commercial Palladium.
Permeability at Low Temperatures. V ictor L om bard an d Charles E ichner (B ull. Soc. chim. France, 1935, [v], 2, 1555-1577).—W hen a foil of pure p alla
dium is arran g ed so th a t on one side there is a vacuum an d on th e o th er a pressure of 1 atm . of hydrogen, th e ra te o f diffusion of th e hydrogen thro u g h the m etal a t T ° C. is such th a t th e volum e of th e gas w hich passes th ro u g h 1 cm .2 o f th e m etal 1 mm . th ic k in 1 h r. is 9-55711'2 . e '1279/y, w hen T = 250°-650° C.
A t tem p eratu res below 250° C. diffusion decreases rapidly, th e ra te a t 125° C.
being only 0-0005 tim es th a t a t 225° C.—A. R . P .
On the Mechanism of Electrodiffusion of Hydrogen Through Palladium.
N. I. Kobosew an d W . W . M onblanowa (Acta Physicochim. U .K .S .S ., 1934, 1, 611-650).— [In G erm an.]
♦Adsorption of Oxygen and the Catalysis of Hydrogen Peroxide by Platinum.
V. A. R o iter an d M. G. Leperson ( Visti Ukrainskogo Naukovo Doslidchogo In stitu tu Fizichnoi K hem ii, 1 9 3 4 ,4 ,4 1 -4 8 ; B rit. Chem. Abs., 1935, [A], 1068).—
[I n U krainian.] Most of th e oxygen adsorbed b y platinum in anode polarization a n d all th e hydrogen adsorbed by p latin u m in cathode polarization reacts w ith hydrogen peroxide. I n th e electrolysis of dilute sulphuric acid there is no sorp
tio n o f electrolytic gas a t eith er electrode if a sufficient [hydrogen peroxide] is m ain tain ed (anode 0-5% , cathode 1-8% o f hydrogen peroxide). Cathodic polarization increases th e cata ly tic a c tiv ity of p latin u m in the decomposition of hydrogen peroxide. Anodic polarization decreases it. The activ ity is con
s ta n t if electrolysis occurs in presence of hydrogen peroxide.—S. G.
♦The Effect of Adsorbed Gases on the Photoelectric Emissivity of Iron and Platinum. A. K e ith Brew er (J. Am er. Chem. Soc., 1932, 54, 1888-1900).
♦The Influence of Gases on the Photoelectric Effect of Platinum. E rn st S ch aaf (Z . physilcal. Chem., 1934, [B], 26, 413-427).—S. G.
The Rate of Solution of Sodium in Solutions of Methyl- and Ethyl-Alcohol in Benzene, Toluene, and Xylene. J . Szper (J. Chim. physique, 1935, 37, 447- 454).— The ra te of solution of sodium in solutions of m ethyl- and ethyl-alcohol in benzene, toluene, a n d xylene is found to decrease w ith dim inishing concen
tr a tio n o f th e alcohol in solution, an d is proportional to th e concentration of H + ions in th e solution. Solution is a process of th e n a tu re of diffusion.—J . T.
♦Vapour Pressure Curves of Thallium at Very Small Vapour Densities. F.
M uller (IId v . Pliys. Acta, 1935, 8, 152-164; Sci. A bs., 1935, [A], 38, 647).— [In G erm an.] By m eans o f the m ethod of line absorption a relative determ ination o f th e v ap o u r pressure of th alliu m was m ade in th e range o f pressure from 1-2 X 10"6 to 7-4 X 10-1 m m . m ercury. The following form ula for th e vapour pressure w as found suitable for th e region from 350° to 1200° C. : logw p =
— 52-23A / T -j- B , where A an d B are co n stan ts depending on th e tem perature.
—S. G.
♦The Influence of Mechanical Deformation on the Rate of Transformation of Polymorphic Metals [Tin]. E rn s t Cohen, W. A. T. Cohen de Meester, and A. K . W. A. v an L ieshout (Proc. K . A kad. Wet. Amsterdam , 1935, 38, 377-387).
-—[In G erm an.] See also M et. Abs., th is vol., p. 415. D eform ation of w hite tin by rolling, draw ing, or bending is shown to increase v ery considerably the velocity o f tran sfo rm atio n ( V) of th e m etal into th e grey modification. Tem pering a fte r deform ation reduces V v ery considerably. V depends on the in te n sity of th e deform ation increasing w ith increased deform ation.—J . T.
♦The Magnetic Anisotropy of Crystals of Tin and of Tin with Added Antimony, Cadmium, and Gallium. (Hoge.) See p. 581.
*1.— The Adsorption of Hydrogen on Tungsten. II.—Some Properties of Adsorbed Films of Oxygen on Tungsten. III.—Composite Films of Oxygen and Hydrogen on Tungsten. J . K . R o b erts (Proc. Roy. Soc., 1935, [A], 152, 445 4 6 3 ,4 6 4 -4 7 7 , 477—480).—Cf. M et. A bs., th is vol., p. 92. (I.— ) The adsorp-
1935
/ . — Properties o f Metals 561
tion of hydrogen on a bare tu n g sten wire is studied experim entally. The p ro cess is one of chem i-sorption. There is one atom of hydrogen per atom ol superficial tu ngsten. The h eat of adsorption w hen a hydrogen molecule strikes a bare tu n g sten surface is 45 kilocals. per mol. H 2; if th e hydrogen molecule strikes a place where 2 adjacent tu n g sten atom s are bare an d all surrounding places are covered, th e h eat of adsorption is 18 kilocals. per mol.
H 2. (I I.— ) The h e a t of adsorption an d th e am ount o f oxygen in th e well- known stable adsorbed film have been m easu red ; a second m olecular film has been found. T h e m echanism of th e adsorption process is discussed. (I I I .— ) The adsorption of oxygen on a surface already covered w ith hydrogen is in v e stig a te d ; when an oxygen molecule is adsorbed, a hydrogen molecule is throw n off from th e surface. The behaviour of hydrogen a t a surface p artially covered w ith oxygen is also investigated.—J . S. G. T.
♦Emissive Power of Tungsten in the Ultra-Violet at High Temperatures. I . Hoffm ann an d H . W illenberg (P hysikal. Z ., 1934, 35, 713-715).— S. G.
♦Measurements of the Thermal Expansion of Cast and Rolled Zinc. H.
G oulboum e Jones (Proc. Phys. Soc. 1935, 47, 1117-1128).—The coefficients of expansion of sm all specimens of cast an d rolled zinc were determ ined in conditions of steady an d of continuously increasing tem p eratu re, an d m arked differences betw een th e coeffs. were found. On rolling, th e random orientation o f crystals in th e cast specim en is broken up, an d m ost of th e long axes are set perpendicular to th e plane of rolling. N o change is produced in th e volum e coeff. of expansion b y rolling. W hen th e zinc crystals are sm all, th e con
tinuous expansion is also sm all, b u t as th e crystal size increases th e continuous expansion also increases. D iscontinuities in th e continuous expansion are associated w ith the long axis of th e crystals. I t is suggested th a t very sm all specimens give rise to a n anom alous effect th a t would n o t be detected in large specimens, an d th a t th e grow th of zinc crystals during heating m ay affect th e expansion of th e zinc. Values of th e constants a, ft, y, 8 in th e expansion form ula L = L J 1 + at + jSP + yP + Si4) are derived as follows : unannealed cast z in c ; a = 27-84 X 10~®; ft = — 47-52 X 10~9; y = 1-78 X 10 12; 8 —
— 18 X 10- 15; annealed cast zinc; a = 29-65 X 10“6; ft — 10-84 X 10 ; y = _ 68-4 X 10-12; S = 129 X 10“15.—J . S. G . T.
♦The Exact Measurement of the Specific Heats of Solid Substances at Higher Temperatures. X IX —The Specific Heats of Zinc, Magnesium, and Their Binary Alloy MgZn2. T. J . P oppem a an d P . M. Jaeg er (Proc. K . A k id . Wet.
Amsterdam, 1935, 38, 510-520).— [In English.] The m ean specific h eats cp of zinc a t tem peratures, t° C., betw een 100° an d 360° C. are found to be given b y c = 0-93335—0-389 X 10-fi + 0-4236 X 10"7«2; th e tru e specific heats, c are given by cp = 0-93335-0-778 X 1 0 '6f + 0-12708 X lO '6«2; th e atom ic heats a t c o n sta n t pressure are given b y Cp = 6-1013—0-50858 X 10*4i + 0-83073 X 10"5i2. The formula: are n o t applicable betw een 165° an d 175° C.
nor betw een 330° an d 340° C. where discontinuous changes in th e m etal have been definitely established to occur. A t 0° C. Gp has th e value 5-935. A p
proxim ate values of CL th e atom ic h e a t a t co n sta n t volum e, are derived as follow s: 100° C., 5-528; 200° C., 5-548; 300° C., 5-714; 400° C., 6-022.
Values of c for m agnesium for various ranges of tem p eratu re betw een 100°
an d 550° C .V e ta b u la te d . Values of cp w ithin th is tem p eratu re range are given by cp = 0-241306 + 0-1052836 X 1 0 - 0-4725 X lO“10«2. V alues of C , th e atom ic h e a t a t co n stan t pressure, are given by Cp = 5-8637 + 0-25585 f — 0-1148 X 10‘8f2. V alues of cp, th e m ean specific h eat, of MgZn2 w ithin th e range 100° are given by c = 0-113545 + 0-21902 X 10"4i. V alues of c are given by c„ = 0-113545 + 0-43804 X 10*4i, while values o f Cp , the m olecular h eat, are given b y Cp = 17-60604 + 0-679216*X 1 0 '2i. The alloy shows no polym orphic tran sfo rm atio n . A volum e contraction of a b o u t 8%
occurs in th e form ation of th e alloy from th e elem ents.—J . S. G. T.
562 Metallurgical A bstrads
Vo l. 2*Metallic Cohesion (Bindung). P au l Gombas (Z. Physik, 1935, 94, 473-488).
—A th eo ry o f th e binding forces in m etals is developed. I t is assum ed th a t th e binding energy in a m etal is associated w ith th e electrostatic in teractio n of th e positive ionic lattice w ith th e uniform ly-distributed electron gas composed of m etallic electrons. The theory is applied to calculated values of th e lattice c o n sta n t (8), h e a t o f sublim ation (s), an d com pressibility (K ) o f potassium w ith th e following results (experim ental values in b ra c k e ts ): 80, 4-52 A., (5-15 A .); a, 20-8 k. cal./m ol. (26-5); k, 1 1 X 10’11 cm .2/dyne (2 0 X 1 0 '11).
N o em pirical param eters are involved in th e calculations. (See also following a b stra c t.)—J . S. G. T.
Theory of the Alkali Metals. P a\il Gom bas (Z . P hysik, 1935, 95, 687-691).
—I n co n tin u atio n o f previous w ork (see preceding ab stract), G. im proves th e th eo ry an d derives th e following values for certain physical co n stan ts in the case o f p o ta s siu m : la ttic e c o n sta n t, 5-43 A .; la ttic e energy, 112-4 k.cal./
m o l.; com pressibility, 2-6 X 10"11 cm .2/d y n e ; com pared w ith respective experim ental values 5-15 A .; 126-2 k .c a l./m o l.; 2-0 X 1 0'11 cm .2/dyne.—J . T.
*0ptical Constants of the Alkali Metals. M. I. Sergeev an d M. G. Chemi- kovskii (Physikal. Z . Sow jetunicn, 1934, 5, 106-114).— [In English.] See a b s tra c t from R ussian source, M et. A bs., th is vol., p. 93.—S. G.
*Influence of Temperature on the Plasticity of Crystals. Pol E . Duwez (P h y s. Rev., 1935, [ii], 4 8 ,484).—A b stra c t o f a p ap er read before the American P hysical Society. The th eo ry o f th e p la stic ity of crystals recently published (M et. A bs., th is vol., p. 293) has been extended in order to tak e into account the influence o f te m p e ra tu re on th e stre s s -s tra in curve. The model of th e de
form ed cry stal, deduced from Zw icky’s secondary stru ctu re theory, shows th a t th e tw o q u a n titie s G an d r max, i.e. th e m odulus of elasticity an d the stress producing ru p tu re o f th e cry stal, are dependent on th e tem perature. F u rth er, G a n d vmax v a ry independently. The relatio n betw een stress and strain , therefore, rem ains th e sam e, w ith G an d TmaT. functions o f T instead of con
sta n ts . T he v a ria tio n of G is know n for a num ber o f m etals over a wide range o f te m p e ra tu re . I n general, a lin ear function can be used, except in the neighbourhood o f crystallographic or m agnetic tran sitio n points. Very few d a ta are available concerning th e tem p eratu re dependence of r max. for single cry stals. M any polycrystalhne m etals were studied u p to th eir m elting p o in ts. I t seem s probable th a t Tm ai is a function o f th e ratio T \ T m, T m being th e m elting tem p eratu re. The curve r max. ( T / T m) is characteristic and is alm ost a s tra ig h t line, except for values o f the ra tio T \ T m approaching 0 an d 1. Sim ple th eo retical calculations m ay explain th e general form of the fu n ctio n r mal. ( T / T J . — S. G.
*New Method for Studying the Plastic Deformation of Metals. L. V.
N ik itin a n d V. 0 . Sochevanov (Metallurg (M etallurgist), 1935, (1), 23-34).—
[In R ussian.] T he deform ation o f iro n an d some non-ferrous m etals was stu d ie d by m easurem ents o f th e electrode po ten tial. The shape o f the p o te n tia l-lo a d curve is closely connected w ith th e degree o f deform ation, and th e curve shows th e elastic lim it m ore precisely th a n do extensom etric m easure
m ents. As th e specim en elongates th e p o te n tia l becomes m ore negative owing to th e increase in in tern al energy. The m ethod enables m easurem ents to be m ade o f stresses in localized portions o f m etallic stru ctu res.—N. A.
*Hyperbolic Paraboloid of Volume Deformation. Ig. M. P av lo v (Metallurg (M etallurgist), 1935, (2), 88-100).— [In R ussian.] The plane diagram of deform ation (the relatio n betw een longitudinal an d tran sv erse deform ation) is im p o rta n t b o th for th e generalization o f th e various m ethods o f pressure w orking a n d fo r u nderstanding th e phenom ena o f applied deform ation and la te ra l extension. T h e space diagram o f th e general expression o f deform-
nr t D JL J jr
a tio n r - = ~ (w here ¡- = stretching, r- = longitudinal deform ation,
h Jj fo
1935 7
.— Properties o f M etals 563
= transverse deform ation) has an inclined surface w hich is a hyperbolic paraboloid. Such a diagram is critically exam ined an d th e influence thereon
of various factors considered.—N. A. . . .
tThe Exploitation, by the Engineer, of the Resistance of Materials. M. A.
C aquot (Génie civil, 1933,1 0 3 ,436).—R ead before Société des Ingénieurs Civils.
Deals largely w ith th e resistance of m aterials to altern atm g stress. . . • A Note on the Surface Temperature of Sliding Metals. F . P . Bowden and K . E . W. R idler (Proc. Cambridge Phil. Soc., 1935, 31, 4 3 1 ^ 3 2 ).—A simple calculation shows th a t if one body slides on an o th er th e tem p eratu re a t th e rubbing surfaces m ay a tta in a very high value. L ead, sliding on steel w ith a velocity of 1570 cm ./second, is found, experim entally, to a tta m a surface te m p eratu re of 327° C. (m elting p o in t 328° C.). J . S. G. T.
♦Calculation of the Heats of Relaxation of Metals from Recrystallization Data. J . A. M. v an L iem pt (Z. P hysik, 1935, 96, 5 3 4 - 5 4 1 ) .- I t is shown th a t th e h eat of relax atio n E of a m etal can be calculated from th e eq u atio n h*
4-6(7 + 1200/3, w here C denotes th e recrystallization co n stan t an d fi is th e degree o f physical deform ation characterizing recrystallization. A pproxi
m ately, E = 4-6 C or, m ore nearly, E = 80T R where T n is th e tem p eratu re of recrystallization. A nother approxim ation is E = 32 T s, where T , denotes th e m elting point. V alues of E for iron, nickel, gold, silver, copper, alum inium , p latinum , ta n ta lu m , tu n g sten , m olybdenum , an d lead are calculated an d are found to be in good agreem ent w ith values otherwise obtained, l h e th erm a diffusion formulae o f L angm uir an d of v. L. are briefly discussed.— J . b. rf. 1.
♦The Diffusion of Gases Through M etals—I. C. J . Sm ithells an d Ü. E . R ansley (Proc. Roy. Soc., 1935, [A], 150, 172-197; andl (su m m ary ) M etal
lurgist (Suppt. to Engineer), 1935, 10, 6 8 - 7 1 ) .-T h e ra te of diffusion of h y d ro gen th ro u g h copper, nickel, iron, an d m olybdenum , an d of nitrogen thro u g h m olybdenum was determ ined over a wide range of tem p eratu re an d pressure.
The effect of tem p eratu re is satisfactorily represented b y th e exponential term in R ichardson’s equation. The effect of pressure is only approxim ately represented b y th e equ atio n D = k V P , th e deviation from th is relatio n being m ost m ark ed a t low pressures. All published d a ta are exam ined an d found to ex h ib it th e sam e deviation. A n allowance is m ade for th e fractio n of tn e surface covered b y adsorbed gas, by introducing th e L angm uir isotherm , and th e equation D = K x/P (a P (l + aP)) accurately represents th e experim ental results. The effect of adsorption on diffusion is em phasized, a n d i t is shown th a t a c tiv a te d adsorption is necessary for diffusion to ta k e place. A dsorption coeffs. can be determ ined from diffusion m easurem ents b y m eans of th e above equation. No diffusion of argon or helium could be detected w ith an y m etal, an d if i t does occur th e ra te is n o t m ore th a n 1 0 '6 tim es th e ra te for th e comm on gases. The ra te of diffusion of hydrogen th ro u g h a single cry stal of iron is the sam e as thro u g h o rdinary fine-grained iron.—Authors. . __
♦Adsorption of Alkali Metals on Metal Surfaces. IV.— Adsorption of Atoms Next to Ions. V.—Influence of Temperature on the Normal Photoelectric Effect. VI.— The Selective Photoelectric Effect. J . H . de B oer an d C. 1 . Veenem ans (Physica, 1935, 2, 521-528, 529-534, 9 1 5 - 9 2 2 ) .- [ I n E n g lis h .^
♦The Vapour Pressure of Metals. F . F . Coleman (U niv. Oxford Abstracts of Dissertations Doctor Philosophy, 1934, 6, 140-143).—T he v ap o u r pressures of m agnesium , th alliu m , an d zinc were determ ined b y a refinem ent o f E g e rto n s m odification of K n u d sen ’s effusion m ethod. The data, obtained satisfy th e following gaussian ro o t m ean square straight-line equations : for m agnesium lo a n = — 7219/T + 8-125; for th alliu m , lo g p = — 9125/T + 8-216, an d for zinc lo g o = - 6533/ T + 8-515, where T is th e absolute tem p eratu re.
The slopes of these equations give th e following values for th e h e a ts of ev ap o ra
564 M etallurgical Abstracts
Vo l. 2tio n : m agnesium 33,027 ± 260 a t 711-0° abs., th alliu m 41,746 ± 330 a t 878-7° abs., an d zinc 29,886 ± 120 a t 605-2° abs. E v alu atio n of th e chem ical c o n stan ts o f these m etals from th e d a ta obtained shows good agreem ent w ith th eo ry only in th e case o f th a lliu m ; th e reason for th e anom alous resu lts for m agnesium an d zinc is discussed.—A. R . P.
*The Sputtering oi Metals by Incidence of Slow Ions, and Measurement of the Threshold Values of Sputtering (Voltage). H einrich Liider (Z. Physilc, 1935, 97, 158-170).—The sp u tterin g of various m etals b y incidence u pon th em of slow argon or alkali ions is investigated. The following threshold values o f th e sp u tterin g voltages for the respective voltages were found. (1) W ith argon : nickel, 7 v . ; copper, 12 v . ; iron, 14 v . ; tu n g sten , 24 v. (2) K + ion w ith tu n g sten , 36 v . ; Cs+ ion w ith tu n g sten , 15 v . ; L i+ ion w ith tu n g sten , 80 v . ; C s+ ion w ith copper, 15 v. The results agree b e tte r w ith theoretical results calculated in accordance w ith H o lst’s th eo ry th a n w ith those deduced from L an g m u ir’s th eo ry .—J . S. G. T.
*A New Method and Apparatus for the Production of Highly-Dispersed Phases. B. Claus (Z. tech. Physilc, 1 9 35,16, 80-82).—A p p aratu s for producing highly-dispersed phases, m ore especially o f m etals, em ploying a high-frequency q u a rtz piezo-oscillator, is described an d illu strated by reference to results o b tain ed w ith m ercury, silver, iron, an d p latin u m .—J . S. G. T.
*The Reflection of Some Metals (Copper, Zinc, Nickel, Silver, Hochheim Alloy) in the Spectral Region from 300 to 186 m g. F ran z H lu 'k a (Z . Physilc, 1935, 96, 230).-—V alues o f th e reflection coeffs. o f copper, zinc, nickel, silver, a n d H ochheim alloy in th e spectral region 300-186 m p were determ ined.
—J . S. G. T.
On the Reflection Factor of Very Thin Films of Metal. Pierre R o u ard (Rev.
d Optique, 1934, 13, 23-79).—The reflection facto r of th in films o f gold and silver deposited on glass w as m easured for varying thicknesses o f film and w ave
lengths o f lig h t a t th e a ir-m e ta l an d g lass-m etal surfaces. I n th e la tte r case, th e reflection facto r decreased to a m inim um w ith increasing thickness of the film, an d subsequently increased : th e position o f th e m inim um depended on th e w ave-length, w hich also influenced th e thickness of film a t which the m inim um occurred. The corresponding curve for the m e ta l-a ir surface showed a d is tin c t d iscontinuity. N orm ally incident w hite light produced ch aracter
istic colour effects in th e case of th e m etal-glass surface.—P . M. C. R .
Parachor and Entropy of Metallic Elements. B inayendra N a th Sen (J.
Chim. physique, 1935, 32, 300-302).—V alues of th e entropy, S , o f th e elem ents copper, m ercury, alum inium , zinc, lead, potassium , sodium , an d cadm ium are calculated using d a ta relating to th e parachor, atom ic radius, atom ic weight, m elting point, atom ic h eat, an d valency which are ta b u lated . S atisfactory agreem ent is found betw een observed an d calculated values of S.
—J . S. G. T.
Influence of Polarization on Photo-Voltaic Effects. Marie Theodoresco (J. Chim. physique, 1934, 31, 433—438).— The photo-voltaic effect observed w ith a copper electrode covered w ith cuprous or cupricoxide indicates th a t th e surface o f th e electrode is irreversibly changed by polarization.—J . S. G. T.
Photoelectronic Effect of Incandescent Metals. C. M. I. Vercelli (A tti Acad.
Sci. Tornic, 1934-1935, 7 0 ,462-471; Sci. A bs., 1935, [A], 38, 961).— The theory o f th e photoelectronic effect o f surfaces (H allw ach’s effect), p u t forw ard by Fow ler, leads to th e confirm ation th a t th e photo-therm oelectronic effect observed by Deaglio is a H allw ach’s effect produced a t high tem p eratu re by light of frequency n o ta b ly lower th a n th e photoelectronic frequency lim it.
g Q The Volta Effect and the Peltier Effect. Filippo Odone (Nuovo cimento, 1935, 12, 273-284; C. Abs., 1935, 29, 7145).— S ta rtin g from D uhem ’s th erm o dynam ic th eo ry o f electrical phenom ena in m etallic conductors, O. shows th a t
1935
I . — Properties o f M etals 565
there is an in tern al an d an ex tern al V olta efiecfc an d relations betw een them an d th e P eltier effect are derived.—S. G.
*Displacement of the Curie Point by Tension. E . E n g lert (Z . P hysik, 1935, 97, 94-96).—No displacem ent o f th e Curie p o in t o f a wire due to tension could be fo u n d ; a n y such displacem ent (w hich was w ithin th e lim it o f experim ental error) as did occur was certainly less th a n of th a t found b y R ay-C haudhun (3let. Abs. (J. In st. Metals), 1931, 47, 642).^-J. S. G. T.
*The Effect of Magnetization on Young’s Modulus of Elasticity of Some Ferromagnetic Substances. K iyosi N akam ura (Set. Rep. Tdhoku Im p . U niv., 1935, [i], 24, 303-331).— [In English.] Three m ethods for m easuring Y oung’s m odulus an d its v ariatio n in ferrom agnetic substances are described together w ith suitable m eans for overcom ing possible sources of error. F o r electrolytic iron a n d cobalt Y o u n g ’s m odulus (E ) rem ains const, on m agnetization of th e m etal, b u t for electrolytic nickel it increases alm ost linearly w ith th e in ten sity of m agnetization (I), th e increase in th e value of E being 17% w hen I = 479 c.g.s. u n its. In nickel-iron alloys E varies w ith th e nickel content, reaching a pronounced m in im u m a t 30% nickel [Note by Abstractor : This value is ta k e n from th e graph, in th e te x t 40% nickel is said to be th e m inim um ] an d a vague m a x im u m a t 85% nickel. The value of d E jE produced b y m agnetization of iron-nickel alloys is very sm all an d negative u p to 30% nickel, th e n increases rapidly to a m axim um a t 50% nickel, decreases to a m inim um a t ab o u t 70%
nickel, an d finally again increases rapidly.—A. R . P.
Thermo-Dynamics of Stationary Systems. I.— The Thermo-Element.
II.— The Diffusion Element. B. B ru is (Proc. Roy. Soc., 1935, [A], 151, 640- 651, 651-665).— (I.— ) The in tro d u ctio n of tw o a rb itra ry assum ptions into the discussion o f th e therm odynam ics of sta tio n a ry system s leads to th e result th a t th e problem o f th e therm o-elem ent can be reduced to a knowledge of th erm al an d electrical conductivities. (II.— ) E quations connecting th e H elm holtz coeff. w ith th e P eltier coeff. an d th e coeff. of th e homogeneous effect, an d w ith th e coeffs. o f diffusion an d electrical conductivity are derived. The problem o fth e diffusion elem ent is th u s reduced to a knowledge of diffusion and electrical conductivity.—J . S. G. T.
Diamagnetism of Elements in the Powdered State. Mulk R aj Y erm a an d I. C. G upta (Current Sci., 1935, 3, 611-612; C. A bs., 1935, 29, 6116).—The change in m agnetic susceptibility of b ism uth, antim ony, gold, silver, an d selenium , w ith particle size is critically reviewed. D h a rm a tti’s w ork w ith selenium (N ature, 1934, 134, 497) w as're p e a te d . B y ta k in g ad equate p re cautions to p rev en t oxidation an d o th er contam ination, th e m agnetic suscepti
b ility was found to be independent of th e particle size. O xidation is probably th e m ajor cause of th e v ariatio n s of m agnetic susceptibility w ith particle size th a t have been reported.—S. G.
Colloidalization and Cold-Working of Metals. S. R am ach an d ra R ao (Current Sci., 1935, 4, 24r-25; C. A bs., 1935, 29, 7246).—N on-ferrom agnetic m etals are assum ed to consist of a lattice o f m etallic ions, th e rem aining elec
tro n s being associated w ith tw o or more nuclei, an d considered as free or p a rtly bound in accordance w ith th e ir relative energy values. The m agnetic suscepti
b ility o f th e m etal is th e sum of th e susceptibilities of th e ions an d of th e valency electrons. The first is c o n s ta n t; th e second is influenced b y physical conditions. I f th e valency electrons have large orbits, or are loosely a tta c h e d to tw o close atom s, as in 'g ra p h ite an d bism uth, diam agnetism decreases on colloidalization, since large orb its are impossible a t th e surface. I n good conductors, such as copper an d silver, th e electrons on th e surface of th e atom s are free. Cold-working o f these m etals gives rise to increased diam agnetism because of (1) d im in u t i o n of free electrons an d of th e param agnetic com ponent (caused b y expansion) an d (2) th e increase in th e diam agnetic com ponent due to th e increased n um ber of bound electrons. The sam e effect w as produced in
copper b y colloidalization (in a n in e rt organic liquid, in th e absence of air).
The discussion of th e effect of im purities given b y V erm a an d G u p ta (preced
ing ab stra c t) is criticized.—S. G.
*A Note on the Hall and Magneto-Resistance Effects. D. Schoenberg (Proc.
Cambridge P hil. Soc., 1935, 31, 271-276).—K ohler (A nn. P hysik, 1934, 20, 878, 891) on th e basis of experim ental w ork b y V erleger (Met. A bs., 1934, 1, 593) has questioned th e v alid ity of th e usual assum ption th a t th e linear H all effect is entirely perpendicular to th e cu rren t, as assum ed by V oigt. T he ex p eri
m en tal w ork of v an E verdingen supports th e p erpendicularity hypothesis. The rejection of th is hypothesis leads to th e conclusion th a t th e m agneto-resistance o f a polycrystal or single crystal, e.g. bism uth, should differ for opposite direc
tions o f th e m agnetic field in th e c ry s ta l; th is is found n o t to be th e case an d th e p erpendicularity hypothesis is established as valid in th e case of bism u th a t least. A new ty p e of H all effect is p red icted b y th e analysis. T he dissym m e try of th e H all effect is discussed an d some of K ohler’s results are generalized a n d are to be investigated fu rth e r.—J . S. G. T.
The Variation of Thermal E.m.f. with Magnetization. F . W oodbridge C o n stan t (P h y s.R e v ., 1935, [ii], 47, 794).—A b stra c t of a p ap er read before the A m erican P hysical Society. T he v a ria tio n o f th e e.m.f. of a therm ocouple w hen one o f th e m etals is m agnetized was first discovered b y W illia m Thomson in th e case o f iro n an d nickel. T his m eans th a t a couple m ay be formed en tirely o f one m a te ria l p rovided th a t th e m agnetization is n o t th e same th ro u g h o u t. I n spite of m an y investigations o f th is effect since Thom son’s o bservation, th e resu lts are conflicting an d th e conclusions confusing. This p a p e r a tte m p ts (1) to sum m arize previous w ork, an d (2) to re p e a t m easure
m en ts o f th e effect on as m an y different ferrom agnetic m etals as possible, in e x actly th e sam e conditions, in order th a t th e resulting d a ta m ight be more available for in te rp re ta tio n . Iro n , nickel, cobalt, an d Perm alloy were tested b y com parison of th e ferrom agnetic m etal first unm agnetized an d th en m ag
n etized in a uniform m agnetic field ag ain st copper. There are indications of a connection betw een th is effect, th e change of length in a m agnetic field and c ry s ta l s tru c tu re w hich is o f in te re st as regards theories o f ferrom agnetism .
—S. G.
*The Variation with Magnetic Field and Temperature of the Thermoelectric Properties of Ferromagnetics. F . E . Lowance an d F . W oodbridge C onstant (P hys. Rev., 1935, [ii], 48, 257-260).—I t is know n th a t a therm ocouple m ay be com posed entirely of iron or nickel provided th a t th e m etal is p a rtly in and p artly outside a m agnetic field. P revious w ork on th is subject is reviewed. M easure
m ents on iron, nickel, cobalt, an d Perm alloy from room tem p eratu re to above th e Curie p o in t indicate th a t th e e.m.f. produced by a m agnetic field in these therm ocouples is conditioned by (1) th e cry stal stru ctu re, an d (2) th e change in d irectio n of th e resulting spins or intrinsic m agnetization in separate crystal regions, an d th a t th is effect is related to th e change o f length on m agnetization.
—J . S. G. T.
M agnetism —I. R . B ecker an d L. L andshofi (Die P hysik, 1935, 3, 9 1 - 108; Sci. A bs., 1935, [A], 38, 671).—A review of th e ra p id developm ents of know ledge o f m agnetism which has ta k e n place m ore p articu larly during th e p a s t 8 years, bro u g h t a b o u t by th e discovery of electron spin an d th e applica
tio n o f q u an tu m m echanics. More ex act calculations were m ade possible, especially in dia- an d p ara-m agnetism , w ith consequent reaction on experi
m en tal investigations. The dem ands for im proved q u a lity o f m agnetic m a te ria l in electrotechnics h as also led to num erous researches an d to a deeper in sig h t in to th e process o f m agnetization. The subjects d e a lt w ith are : diam ag n etism ; ionic su sc e p tib ility ; p aram ag n etism ; rare e a rth s ; th e iron g ro u p ; palladium -, p latin u m -, a n d u ran iu m -tran sitio n groups, hom eopolar molecules an d com binations o f com pound io n s; ferrom agnetism , general
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