Magneto-electric effect in Y1-xRxFeO3 (R = Sm and Er) ceramics

Abstract

In the present work, we synthesize a series of Y1-xRxFeO3R=Er,Sm&0.≤x≤1 polycrystalline compound by solid-state reaction method to study the A-site substitution effects on physical properties in YFeO3. The Rietveld refinement of X-ray diffraction analysis indicates that with Er3+ substitution, the lattice parameters have decreased, and more structural distortion has been shown compared to Sm3+ substitution. The obtained magnetic hysteresis loops reveal that Er3+ ions have induced an antiferromagnetic behavior in YFeO3 because of a reduction in the Dzyloshinskii-Moriya interaction. The Y1-xSmxFeO3 family, however, shows a weak ferromagnetic behavior. Furthermore, due to the spin reorientation (SR) transition, a distinct anomaly has been detected in the temperature dependence of Ac susceptibility and dielectric constant curves. With substituting Sm at the Y-site in the YFeO3 compound, SR transition happens at a temperature, TSR, in which the spin structure changes high-temperature Γ4 to Γ2 configuration, and therefore the starting and ending of the SR region depend on Sm concentration. Interestingly, we have observed a gigantic dielectric constant in Y0.7Sm0.3FeO3, Y0.5Er0.5FeO3, and Y0.25Er0.75FeO3. It, however, has demonstrated that Y0.7Sm0.3FeO3 is the only compound that shows a relaxor ferroelectric behavior. The observed peak in the temperature dependence of the dielectric constant has also described a magnetic transition temperature indicating the magneto-dielectric effect in our studied samples.