Magnetoelectric properties of multiferroic CuCrO2 studied by means of ab initio calculations and Monte Carlo simulations

Abstract

Motivated by the discovery of multiferroicity in the geometrically frustrated triangular antiferromagnet ${\mathrm{CuCrO}}_{2}$ below its N\'eel temperature ${T}_{N}$, we investigate its magnetic and ferroelectric properties using ab initio calculations and Monte Carlo simulations. Exchange interactions up to the third nearest neighbors in the $ab$ plane, interlayer interaction, and single ion anisotropy constants in ${\mathrm{CuCrO}}_{2}$ are estimated by a series of density functional theory calculations. In particular, our results evidence a hard axis along the [110] direction due to the lattice distortion that takes place along this direction below ${T}_{N}$. Our Monte Carlo simulations indicate that the system possesses a N\'eel temperature ${T}_{N}\ensuremath{\approx}27$ K very close to the ones reported experimentally (${T}_{N}=24--26$ K). Also we show that the ground state is a proper-screw magnetic configuration with an incommensurate propagation vector pointing along the [110] direction. Moreover, our work reports the emergence of spin helicity below ${T}_{N}$ which leads to ferroelectricity in the extended inverse Dzyaloshinskii-Moriya model. We confirm the electric control of spin helicity by simulating $P\text{\ensuremath{-}}E$ hysteresis loops at various temperatures.