Spin collinearity and thermal disorder in ε-Fe2O3 -: art. no. 053901

Studies of magnetoelectric epsilon-Fe2O3 nanoparticles (30 nm) in silica by Fe-57 Mossbauer spectrometry (4.2-600 K,0-6 T) are reported. They indicate a magnetic/structural transition at similar to 130 K, a high-temperature collinear ferrimagnetic spin structure similar to FeGaO3 and FeAlO3, and the Curie temperature T-C at 585 K. Reduced hyperfine field versus T/T-C is (S=5/2) Brillouin-like or Langevin-like according to the structural site. The magnetization at 300 K is estimated to 0.25 mu(B)/Fe in accord with published data. (c) 2005 American Institute of Physics.