Magneto-resistance of Nano-Fe3O4/Ag Granular System
Keywords:
half-metallic oxide,
magnetically ordered materials,
nano-granular system,
magneto-resistance
2005 Volume 5 Issue 2 Pages 73-76
Details
2005 Volume 5 Issue 2 Pages 73-76
Four kinds of Fe3O4/Ag granular systems were prepared from sintered mixtures of Fe3O4 and Ag or Ag2O. Magneto-resistances (MRs) were measured at room temperature for samples with Ag volume fraction x between 0 and 0.4. Samples including relatively large Fe3O4 grains showed -1% to -1.4% room temperature MR ratios (MRR) at 1 T. On the other hand, samples including Fe3O4 nano-particles showed large negative room temperature MRR of about -4% to -5% at 1 T near the percolation threshold of χc-0.2. It was suggested that Fe3O4/Ag/Fe3O4 paths were effective for the large IMRRI by the elastic conduction of spin-polarized electrons between Fe3O4 nano-particles. Possibility of spin accumulation in small Ag particles was also shown for this system.
