Magnetism driven ferroelectricity above liquid nitrogen temperature in Y2CoMnO6

TL;DR

This study reports multiferroic behavior in Y2CoMnO6 with ferroelectricity driven by magnetic ordering, achieving transition temperatures above liquid nitrogen temperature, and proposes an exchange-striction model for the phenomenon.

Contribution

It introduces a new multiferroic double perovskite Y2CoMnO6 exhibiting high-temperature ferroelectricity driven by magnetic order, supported by experimental data and a proposed exchange-striction model.

Findings

Ferroelectric transition at 80K in Y2CoMnO6.

Magnetoelectric coupling is small, with ~8% polarization suppression under 5 Tesla.

Hysteretic behavior persists at 5K even under 7 Tesla.

Abstract

We report multiferroic behavior in double perovskite Y2CoMnO6 with ferroelectric transition temperature Tc = 80K. The origin of ferroelectricity is associated with magnetic ordering of Co2+ and Mn4+ moments in a up-up-down-down arrangement. The saturation polarization and magnetization are estimated to be 65 uC/m2 and 6.2 Bohr magneton/f.u. respectively. The magnetoelectric coupling parameter, on the other hand, is small as a 5 Tesla field suppresses the electric polarization by only ~8%. This is corroborated with observed hysteretic behaviour at 5K that remains unsaturated even upto 7 Tesla. A model based on exchange-striction is proposed to explain the observed high temperature ferroelectricity.