Electric Polarization in ErCrO3 Induced by Restricted Polar Domains

TL;DR

This study investigates electric polarization in ErCrO3 crystals, revealing induced polarization from structural polar domains near impurity ions, forming a superparaelectric state without ferroelectric ordering.

Contribution

It demonstrates the formation of restricted polar domains near Bi^{3+} impurities in ErCrO3, leading to superparaelectric behavior, a novel insight into polarization mechanisms in this material.

Findings

Polarization observed without ferroelectric order.

Restricted polar domains form superparaelectric state.

Hysteresis loops with remanent polarization detected.

Abstract

Electric polarization in ErCrO3 single crystals has been investigated in the temperature range of 5_370 K. Ferroelectric ordering has not been found in any of the directions. However, electric polarization induced by restricted polar domains of structural origin has been observed. These domains are formed in the crystal matrix near impurity Bi^{3+} ions partially substituting Er^{3+} ions during the growth of single crystals by the method of spontaneous crystallization using solvent Bi_2O_3. The restricted polar domains form the superparaelectric state. Hysteresis loops with remanent polarization, both along the c axis and in the [110] directions, have been observed below some temperatures T_fr (in the frozen superparaelectric state). The polarization exists up to certain temperatures, which depend on the applied electric field orientation with respect to the crystal axes and exceed significantly temperature T_N of magnetic ordering.