Magnetoelectric interactions in polycrystalline multiferroic antiferromagnets CuFe1−xRhxO2 (x = 0.00 and x = 0.05)

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.

This study shows that research for multiferroic materials may successfully be performed using ceramics. The magnetoelectric phase diagram (Fig. a) for CuFe0.95Rh0.05O2 has been established using magnetic, dielectric and ferroelectric studies. This sample also shows a discontinuity in temperature dependent magnetodielectric coupling (Fig. b).Figure optionsDownload as PowerPoint slide