Direct observation of magnetism controlled by electric fields for CoFeB mesoscopic islands on PMN-PT

Abstract

Electric field control of magnetism at the microscopic scale is vital for high-density magnetic storage, and has developed rapidly in recent years. Here, we report three types of magnetic responses under in situ electric fields for different mesoscopic CoFeB islands on one PMN-PT single crystal, including Type I, which shows no changes of the magnetic hysteresis under different electric fields, Type II, which shows obvious changes and remains after the electric fields are removed, and Type III, which displays a combined behavior of Type I and Type II. In addition, Type II displays four subtypes according to the relation between coercivity and remanence ratio. These phenomena can be attributed to 109° or 180°/71° ferroelectric domain switching, as well as the complex magnetization reversal mechanism.