Temperature-Dependent Magnetic Properties of Fe-Pt Nanoparticles

Abstract

This project investigated the temperature dependence of the magnetization and anisotropy field of Fe-Pt nanoparticle samples with different order parameters and compositions. A decrease in the order parameter and/or deviation from equiatomic composition brings about a rapid reduction in the magnetization and anisotropy field with increasing temperature. The temperature dependence of the magnetic properties was found to be associated with the probability of Fe atoms being in Ll₀type atomic arrangement, which was obtained using Mossbauer spectroscopy, rather than with the order parameter. The changes in magnetization and anisotropy field correlated with each other and demonstrated a qualitative relationship in agreement with a theory based on magnetic thermal fluctuation.