J. Phys. IV France 07 (1997) C1-513-C1-516
Origin of Elevated Ordering Temperature in MnFe2O4 Nanometer ParticlesA.H. Morrish, Z.W. Li and X.Z. Zhou
Department of Physics, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
Mössbauer spectra of MnFe2O4 with various particle sizes in a longitudinal 50 kOe magnetic field show that the Fe ion occupancy of the A and B crystallographic sites depends on the particle size. The elevated Néel temperatures with decreasing particle sizes are attributed to an increased iron occupancy on the A sites ; this in turn leads to an increase in the total superexchange interaction.
© EDP Sciences 1997