Analysis on the microstructure and magnetic properties of MgGaFeO4 spinel compound

Abstract

AbstractThe single phase of the spinel ferrite MgGaFeO4 is successfully prepared by the high‐temperature solid‐state reaction. The crystal structure, cation distribution, valence state, and magnetic properties are systematically investigated through various techniques in this work. From the analysis of X‐ray diffraction, the face‐centered cubic structure with the space group Fd3m for the single‐phase sample is obtained. The magnetic hysteresis loops M(H) shows a typical magnetic hysteresis behavior at 5 K, while an obvious paramagnetic behavior can be observed at room temperature. The characteristics of magnetic properties suggest that the intrinsic ferromagnetic (FM) interaction and magnetic frustration are cooperated in the system. The specific divergence and irreversibility in the temperature‐dependent magnetization curves M(T) indicate a typical spin‐glass (SG) behavior, which occurring around the freezing temperature Tf = 40 K. Further analysis of the isothermal remanent magnetization (MIRM) suggests the existence of an intensive magnetic frustration state, which leads to stable residual magnetization without decaying under a long time span. More than that, based on the corresponding fitting parameters (τ0 = 8 × 10−12 s, zv = 6.32 and T0 = 56.2 K), the SG state in the sample is further confirmed. The following detailed analyses reveal that the competitions between antiferromagnetic (AFM) and ferromagnetic (FM) interactions definitely exist in MgGaFeO4, which should be the response to motivate the SG behavior.