7th INTERNATIONAL CONFERENCE ON FERRITES

J. Phys. IV France 07 (1997) C1-513-C1-516
DOI: 10.1051/jp4:19971209

Origin of Elevated Ordering Temperature in MnFe₂O₄ Nanometer Particles

A.H. Morrish, Z.W. Li and X.Z. Zhou

Department of Physics, University of Manitoba, Winnipeg, MB R3T 2N2, Canada

Abstract
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