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Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.49 [2011] >
IJPAP Vol.49(03) [March 2011] >
| Title: | Size dependence of magneto-resistive behaviour of nano-particle magnetite |
| Authors: | Choudhary, B L
Krishnamurthy, Anjali
Srivastava, Bipin K |
| Keywords: | Magneto-resistance
Nano-particles
Magnetite |
| Issue Date: | Mar-2011 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Two nano-particle
samples of magnetite have been prepared with average particle sizes of ~260Å
and ~1000Å. Electrical resistance of these samples has been measured in the
temperature range 20-300 K and in magnetic fields up to
7.5 kOe. The two samples exhibit insulating/semi-conducting behaviour at all
the temperatures. They show large magnetoresistance (MR). For the bigger particle’s sample MR is 23% at 300 K and 7.5 kOe at 40 K, the value drops to ~4%.
For the smaller particle’s sample, MR
is only ~4% at 300 K and shows slight increase to ~6% at 40 K. Results are
suggestive of the pre-dominance of the polarized spin dependent contribution to
resistivity. Observed features could be interpreted in terms of large magnetic
anisotropy for surface spins of the nano-particles. |
| Page(s): | 190-194 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.49(03) [March 2011]
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