Fe substitution-controlled anti-polar phase in multiferroic TbMn2O5

Abstract

Magnetic multiferroics TbMn2O5 shows rich magnetic phases that are strongly coupled to multiple electrical phases. Herein, we report that Fe substitutions in TbMn2O5 can selectively and completely suppress the lower-temperature anti-polar phase, whereas the higher-temperature ferroelectric phase is almost intact down to T ≈ 10 K. Neutron diffraction on the single crystalline TbMn2-xFexO5 (x ≈ 0.06) shows that the commensurate magnetic phase persists down to T ≈ 1.7 K, indicating that the commensurability, which is responsible for the exchange-striction mechanism, plays a deterministic role on the ferroelectric polarization in TbMn2O5.