Room-temperature paramagnetoelectric effect in magnetoelectric multiferroics Pb(Fe1/2Nb1/2)O3 and its solid solution with PbTiO3

TL;DR

This study reports the observation of room-temperature paramagnetoelectric effects in multiferroic ceramics Pb(Fe1/2Nb1/2)O3 and its PbTiO3 solid solution, with theoretical modeling explaining the temperature dependence of the effect.

Contribution

First demonstration of room-temperature paramagnetoelectric response in high-resistive multiferroic ceramics with theoretical analysis based on Landau phase transition theory.

Findings

Max PME coefficient about 4x10^(-18) s/A in PFN

PME coefficient peaks near ferroelectric-to-paraelectric transition temperature

Theoretical model reproduces temperature dependence of PME effect

Abstract

We have observed the magnetoelectric response at room temperature and above in high-resistive ceramics made of multiferroic Pb(Fe1/2Nb1/2)O3 (PFN) and PFN-based solid solution 0.91PFN-0.09PbTiO3 (PFN-PT). The value of the paramagnetoelectric (PME) coefficient shows a pronounced maximum near the ferroelectric-to-paraelectric phase transition temperature, T_C, and then decreases sharply to zero for T>T_C. The maximal PME coefficient in PFN is about 4x10(-18) s/A. The theoretical description of the PME effect, within the framework of a Landau theory of phase transitions allowing for realistic temperature dependences of spontaneous polarization, dielectric and magnetic susceptibilities, qualitatively reproduces well the temperature dependence of the PME coefficient. In particular, the Landau theory predicts the significant increase of the PME effect at low temperatures and near the temperature of the paraelectric-to-ferroelectric phase transition, since the PME coefficient is equal to the product of the spontaneous polarization, dielectric permittivity, square of magnetic susceptibility and the coefficient quantifying the strength of the biquadratic magnetoelectric coupling