Low magnetic field reversal of electric polarization in a Y-type hexaferrite

TL;DR

This study demonstrates low magnetic field control of electric polarization in a Y-type hexaferrite, achieving high magnetoelectric sensitivity up to 250 K, with potential for practical multiferroic applications.

Contribution

It reports a new multiferroic material with magnetically tunable ferroelectricity and giant magnetoelectric sensitivity at relatively high temperatures.

Findings

Electric polarization can be controlled by low magnetic fields.

Magnetoelectric sensitivity reaches ~3.0×10^3 ps/m at 200 K.

Ferroelectricity persists even without magnetic field.

Abstract

Magnetoelectric multiferroics in which ferroelectricity and magnetism coexist have attracted extensive attention because they provide great opportunities for the mutual control of electric polarization by magnetic fields and magnetization by electric fields. From a practical point view, the main challenge in this field is to find proper multiferroic materials with a high operating temperature and great magnetoelectric sensitivity. Here we report on the magnetically tunable ferroelectricity and the giant magnetoelectric sensitivity up to 250 K in a Y-type hexaferrite, BaSrCoZnFe11AlO22. Not only the magnitude but also the sign of electric polarization can be effectively controlled by applying low magnetic fields (a few hundreds of Oe) that modifies the spiral magnetic structures. The magnetically induced ferroelectricity is stabilized even in zero magnetic field. Decayless reproducible flipping of electric polarization by oscillating low magnetic fields is shown. The maximum linear magnetoelectric coefficient reaches a high value of ~ 3.0\times10^3 ps/m at 200 K.