Weak ferrimagnets of the YFe1-xCrxO3 type: negative magnetization and spin reorientation

TL;DR

This study investigates the magnetic behavior of YFe$_{1-x}$Cr$_x$O$_3$ weak ferrimagnets, revealing phenomena like negative magnetization, spin reorientation, and temperature compensation near room temperature through a molecular field model.

Contribution

The paper introduces a comprehensive theoretical model accounting for various spin interactions to explain complex magnetic phenomena in YFe$_{1-x}$Cr$_x$O$_3$ ferrimagnets, including room-temperature compensation.

Findings

Temperature compensation occurs at 300 K for x=0.45.

Negative magnetization and spin reorientation are demonstrated.

Magnetic structures of the $G_{xyz}$ type are predicted.

Abstract

In this work, we present an analysis of magnetic properties of weak ferrimagnets of the YFe$_{1-x}$Cr$_x$O$_3$ type. Taking into account the main spin interactions - isotropic Heisenberg superexchange, antisymmetric Dzyaloshinskii-Moriya exchange, single-ion spin anisotropy - calculations of the free energy, concentration and temperature dependences of magnetization were carried out within a framework of a molecular field model. In particular, the model demonstrates the phenomena of temperature compensation and negative magnetization, as well as spin reorientation. The compensation temperature reaches room temperature T = 300 K in a composition with x = 0.45. The existence of magnetic structures of the $G_{xyz}$ type with the spatial orientation of the Neel vector is predicted.