DC magnetization study of nanocrystalline (MnO)i/(ZnO)(1-i) (i=0.2, 0.3, and 0.4)

(1)

DC magnetization study of

nanocrystalline (MnO) /(ZnO)

_i

_(1-i)

(i=0.2, 0.3, and 0.4)

1

1 1, 2

1

3 G. Zolnierkiewicz , J. Typek , N. Guskos , A. Guskos , D. Sibera ,

3 and U. Narkiewicz

1

Institute of Physics, Faculty of Mechanical Engineering and Mechatronics,West Pomeranian University of Technology,

Al. Piastow 48, 70-311 Szczecin, Poland

2

Department of Solid State Physics, Faculty of Physics, University of Athens,

Panepistimiopolis, 15 784 Zografou, Athens, Greece

3

Institute of Chemical and Environmental Engineering, West Pomeranian University of Technology,

Al. Piastów 17, 70-310 Szczecin, Poland

· The superparamagnetic phase has been detected above the blocking temperature T in all investigated samples.B

· The value of the blocking temperature increases with the ZnMnO content.₃

· The value of T determined from magnetization B

measurements is smaller than calculated from FMR spectra ( , ).

· In sample n=0.2 cluster-type behavior of nanoparticles has been detected that formed an internal magnetic field of the ~1 kOe intensity.

Conclusions

The investigated samples were synthesized by the wet chemical method. Initially, an aqueous solution of nitrides was obtained by mixture of manganese hydroxides and zinc hydroxides. Then the obtained hydroxides were filtered, dried at the temperature of 70°C and calcined 1 hour at 300°C. The final sample contained (20, 30 and 40) wt.% MnO and (80, 70 and 60 respectively ) wt.% ZnO. The p h a s e c o m p o s i t i o n w a s determined by X-ray diffraction (CoKá radiation, X'Pert Philips). It was found that the sample contains only two phases: ZnO and ZnMnO . The mean crystallite 3

size was calculated by using Scherrer's formula.

T h e m a g n e t i c m o m e n t measurements were carried in the 2 – 300 K temperature range and up to 7 T using Magnetic Property Measurement System MPMS XL Quantum Design.

Experimental

ZnO ZnMnO3 XRD d [nm] Raman XRD d [nm] Raman 20 wt.% + + 10 + 30 wt.% 100 + 9 + 40 wt.% 100 + 0 50 100 150 200 250 300 0.00000 0.00002 0.00004 0.00006 0.00008 0.00010 0.00012 0.00014 0.00016 0.20 MnO/0.80 ZnO c [ e m u × O e -1 × g -1 ] Temperature [K] ZFC 50 Oe ZFC 100 Oe ZFC 500 Oe ZFC 1000 Oe ZFC 10000 Oe ZFC 70000 Oe 0 50 100 150 200 250 300 0.00000 0.00002 0.00004 0.00006 0.00008 0.00010 0.00012 0.00014 0.00016 0.00018 c [ e m u × O e -1 × g -1 ] Temperature [K] FC 50 Oe FC 100 Oe FC 500 Oe FC 1000 Oe FC 10000 Oe FC 70000 Oe 0.20 MnO/0.80 ZnO 0 50 100 150 200 250 300 0.00000 0.00002 0.00004 0.00006 0.00008 0.00010 0.00012 0.00014 0.00016 0.00018 0.00020 0.30 MnO/0.70 ZnO c [ e m u × O e -1 × g -1 ] Temperature [K] FC 50 Oe FC 100 Oe FC 500 Oe FC 1000 Oe FC 10000 Oe FC 70000 Oe 0 50 100 150 200 250 300 0.00000 0.00002 0.00004 0.00006 0.00008 0.00010 0.00012 0.00014 0.00016 0.00018 0.30 MnO/0.70 ZnO c [ e m u × O e -1 × g -1 ] Temperature [K] ZFC 50 Oe ZFC 100 Oe ZFC 500 Oe ZFC 1000 Oe ZFC 10000 Oe ZFC 70000 Oe 0 50 100 150 200 250 300 0.00000 0.00005 0.00010 0.00015 0.00020 0.00025 0.00030 0.40 MnO/0.60 ZnO c [ e m u × O e -1 × g -1 ] Temperature [K] ZFC 50 Oe ZFC 100 Oe ZFC 500 Oe ZFC 1000 Oe ZFC 10000 Oe ZFC 70000 Oe 0 50 100 150 200 250 300 0.00000 0.00005 0.00010 0.00015 0.00020 0.00025 0.00030 0.00035 0.40 MnO/0.60 ZnO c [ e m u × O e -1 × g -1 ] Temperature [K] FC 50 Oe FC 100 Oe FC 500 Oe FC 1000 Oe FC 10000 Oe FC 70000 Oe 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 0.00009 0.00010 0.00011 0.00012 0.00013 0.00014 0.00015 0.00016 0.00017 0.30 MnO/0.70 ZnO c [ e m u × O e -1 × g -1 ] Temperature [K] ZFC 50 Oe ZFC 100 Oe ZFC 500 Oe ZFC 1000 Oe ZFC 10000 Oe ZFC 70000 Oe 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 0.00008 0.00009 0.00010 0.00011 0.00012 0.00013 0.00014 0.20 MnO/0.80 ZnO c [ e m u × O e -1 × g -1 ] Temperature [K] ZFC 50 Oe ZFC 100 Oe ZFC 500 Oe ZFC 1000 Oe ZFC 10000 Oe ZFC 70000 Oe 0 2 4 6 8 10 12 14 16 18 20 22 24 0.00016 0.00018 0.00020 0.00022 0.00024 0.00026 0.00028 0.40 MnO/0.60 ZnO c [ e m u × O e -1 × g -1 ] Temperature [K] ZFC 50 Oe ZFC 100 Oe ZFC 500 Oe ZFC 1000 Oe ZFC 10000 Oe ZFC 70000 Oe

0.20 MnO/ 0.80 ZnO

_{0.30 MnO/ 0.70 ZnO}

_{0.40 MnO/ 0.60 ZnO}

0.20 MnO/0.80 ZnO 0.30 MnO/0.70 ZnO 0.40 MnO/0.60 ZnO

7.5 8.0 8.5 9.0 9.5 10.0 B lo c k in g T e m p e r a tu r e [ K ] Sample 50 Oe 100 Oe 500 Oe 1000 Oe 0 10000 20000 30000 40000 50000 60000 70000 0 1 2 3 4 5 6 7 8 0.30 MnO/0.70 ZnO M [ e m u × g -1 ] Field [Oe] 2 K 5 K 10 K 40 K 0 50 100 150 200 250 300 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000 0.20 MnO/0.80 ZnO 1 / c [e m u -1 ×O e ×g ] Temperature [K] ZFC50gOeemu ZFC100gOeemu ZFC500gOeemu ZFC1000gOeemu ZFC10000gOemu ZFC70000gOeemu 0 50 100 150 200 250 300 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 0.30 MnO/0.70 ZnO 1 / c [e m u -1 ×O e ×g ] Temperature [K] ZFC50gOeemu ZFC100gOeemu ZFC500gOeemu ZFC1000gOeemu ZFC10000gOemu ZFC70000gOemu 0 50 100 150 200 250 300 0 10000 20000 30000 40000 50000 0.40 MnO/0.60 ZnO 1 / c [e m u -1 ×O e ×g ] Temperature [K] ZFC50gOeemu ZFC100gOeemu ZFC500gOeemu ZFC1000gOeemu ZFC10000gOemu ZFC70000gOemu

DC magnetization study of nanocrystalline (MnO)i/(ZnO)(1-i) (i=0.2, 0.3, and 0.4)