Magnetoelectric interactions in polycrystalline multiferroic antiferromagnets CuFe(1-x)RhxO2 (x=0.00 and x=0.05)

TL;DR

This study investigates magnetoelectric coupling in polycrystalline CuFeO2 and Rh-doped CuFeO2, revealing electric polarization without magnetic fields and different magnetodielectric mechanisms in various magnetic states.

Contribution

It demonstrates magnetoelectric effects in polycrystalline ceramics and highlights the influence of Rh doping on magnetic and electric properties.

Findings

Electric polarization observed without external magnetic field.

Magnetodielectric effect supports noncollinear antiferromagnetic state.

Electric polarization can be suppressed by magnetic field.

Abstract

Magnetoelectric coupling in the polycrystalline antiferromagnets CuFe0.95Rh0.05O2 and CuFeO2 has been investigated. For both samples, electric polarization was observed in the absence of an applied external magnetic field demonstrating that for multiferroic research ceramics are worth to be studied. The observed magnetodielectric effect for CuFe0.95Rh0.05O2 in the electrically polar phase supports the existence of a noncollinear antiferromagnetic state. Interestingly, the electric polarization of this sample can be suppressed by a magnetic field. The temperature dependence of the relative magnitude of the magnetodielectric effect shows a discontinuity, clearly indicating different mechanisms of the magnetodielectric couplings in polar and paraelectric antiferromagnetic states.