Multiferroicity in half-Cr-doped YMnO_3 epitaxial films with compressive strain

摘要

We report on the growth and characterization of epitaxial (010)- and (100)-YMn_(0.5)Cr_(0.5)O_3 films on the corresponding YAlO_3 substrates. It is found that the magnetic transition temperature increases from 75 K for the bulk sample to 120K for the compressive-strained films. Along the c- and a-axes, ferroelectric polarization develops below 120K with the saturation values of 0.17 and 0.05 μC/cm~2, respectively, while it remains zero along the b-axis. Furthermore, it is demonstrated that the ferroelectric polarization can be modulated by magnetic field. The displayed ferroelectric-ity is explainable by considering coexistence of the predominant bc-cycloidal and minor E-type antiferromagnetic orders.