Micromagnetic modeling of the superparamagnetic fraction of Fe3O4–Fe3–x Tix O4 composites

Abstract

Modeling of the hysteresis characteristics of Fe3O4–Fe3–xTixO4 composites was performed using the method of magnetic rectangles. Their magnetic properties are well explained within the model of an ensemble of magnetostatically interacting two-phase chemically inhomogeneous particles. It is shown that accounting for the contribution of the superparamagnetic fraction makes it possible to obtain agreement between the theoretical and experimental magnetic characteristics of the samples. The model allows calculating the magnetization reversal fields and magnetizations of the studied composites theoretically and also to show that the main contribution to the remanent magnetization is made by two phase particles. In addition, a possibility of using this model for samples containing superparamagnetic particles is demonstrated.

Keywords

• magnetic granulometry
• superparamagnetism
• micromagnetic modeling
• magnetostatic interaction
• two-phase particles