Observation of Magnetic-Field-Induced Electric Polarization in Terbium Orthoferrite

In TbFeO3 orthoferrite at temperatures below the antiferromagnetic ordering temperature for the terbium subsystem (similar to 3.2 K), the electric polarization P-a(H-b) induced by a magnetic field H-b along the a axis is found. Such polarization is accompanied by anomalies related to metamagnetic (for Tb) and spin-reorientation (for Fe) transitions. At low magnetic fields |H| < H-cr1 similar to 5 kOe, the P-a(H-b) dependence exhibits a strong hysteresis and has a butterfly shape, while in intermediate-field magnetic configurations, |H-cr1| < |H| < |H-cr2| similar to 18 kOe, the sign of the polarization is determined by the sign of an applied electric field, and the P-a(H-b) dependence turns out to be nonmonotonic. A qualitative explanation of the observed effects is given in the framework of a symmetry analysis of the allowed magnetoelectric interactions in the field-induced magnetic structures.

Automated summary

In TbFeO3 orthoferrite, a magnetic field H-b along the a axis induces an electric polarization P-a(H-b) at temperatures below the antiferromagnetic ordering temperature for the terbium subsystem. This polarization is accompanied by anomalies associated with metamagnetic and spin-reorientation transitions. The observed effects can be qualitatively explained by considering the allowed magnetoelectric interactions in the field-induced magnetic structures.