Electric polarization observed in single crystals of multiferroic Lu2MnCoO6

TL;DR

This study demonstrates intrinsic electric polarization in single crystals of Lu2MnCoO6, revealing magnetoelectric coupling and hysteresis effects driven by magnetic frustration, advancing understanding of multiferroic behavior in this material.

Contribution

It provides the first clear evidence of intrinsic multiferroic behavior in single crystals of Lu2MnCoO6 and models the magnetoelectric coupling mechanism involving magnetic frustration.

Findings

Electric polarization is observed along the b-axis.

Magnetic fields suppress polarization along the c-axis.

The material exhibits coupled hysteretic magnetic and electric properties.

Abstract

We report electric polarization and magnetization measurements in single crystals of double perovskite Lu2MnCoO6 using pulsed magnetic fields and optical second harmonic generation (SHG) in DC magnetic fields. we observe well-resolved magnetic field-induced changes in the electric polarization in single crystals and thereby resolve the question about whether multiferroic behavior is intrinsic to these materials or an extrinsic feature of polycrystals. We find electric polarization along the crystalline b-axis, that is suppressed by applying a magnetic fields along c-axis and advance a model for the origin of magnetoelectric coupling. We furthermore map the phase diagram using both capacitance and electric polarization to identify regions of ordering and regions of magnetoelectric hysteresis. This compound is a rare example of coupled hysteretic behavior in the magnetic and electric properties. The ferromagnetic-like magnetic hysteresis loop that couples to hysteretic polarization can be attributed not to ordinary ferromagnetic domains, but to the rich physics of magnetic frustration of Ising-like spins in the axial next-nearest neighbor interaction model.