Origin of the Ising Ferrimagnetism and Spin-Charge Coupling in LuFe2O4

TL;DR

This study investigates the origin of ferrimagnetism and spin-charge coupling in LuFe2O4 using density functional calculations and Monte Carlo simulations, revealing the magnetic interactions responsible for its properties.

Contribution

It provides a detailed theoretical explanation for the ferrimagnetism and spin-charge coupling mechanisms in LuFe2O4, which were previously not well understood.

Findings

Ferrimagnetism arises from strong antiferromagnetic interactions within and between Fe layers.

Giant magnetocapacitance at room temperature explained by spin-charge coupling.

Enhanced electric polarization at 240 K linked to spin-charge interactions.

Abstract

The spin ordering and spin-charge coupling in LuFe2O4 were investigated on the basis of density functional calculations and Monte Carlo simulations. The 2:1 ferrimagnetism arises from the strong antiferromagnetic intra-sheet Fe3+-Fe3+ and Fe3+ -Fe2+ as well as some substantial antiferromagnetic Fe2+-Fe3+ inter-sheet spin exchange interactions. The giant magnetocapacitance at room temperature and the enhanced electric polarization at 240 K of LuFe2O4 are explained by the strong spin-charge coupling.