Room-Temperature Magnetoelectric Switching and Magnetoelectric Memory Driven by Gate Voltage

Electric-field control of magnetism is one of the most promising routes for developing the energy-efficient magnetoresistive random access memory and spin-logic devices. Of particular interest is the electric-field-induced 180° perpendicular magnetization switching, which currently remains challenging. Here, we experimentally demonstrate the electric-field switching of perpendicular magnetization in a ferrimagnet FeTb in the absence of external magnetic fields. By utilizing ionic liquid gating at room temperature, the ferrimagnetic order can be reversibly switched as a result of the hydrogen injection or extraction under positive or negative gate voltages. Specifically, the hydrogen content pronouncedly modifies the spin and orbital magnetic moments of the Tb sublattice, which subsequently influences the relative magnitude and/or direction of the Fe and Tb sublattice magnetizations, resulting in the switching of ferrimagnetic order. More importantly, we demonstrate a prototype room-temperature three-terminal magnetoelectric memory device by incorporating the giant magnetoresistance effect with electric-field controllable ferrimagnetism. Our results reveal the prosperous aspects of ionic gating for enabling the electric-field-controllable magnetoelectric memory or logic devices.