Control of Compensation Temperature in CoGd Films through Hydrogen and Oxygen Migration under Gate Voltage

Abstract

Electrical control of magnetic properties is crucial for low-energy memory and logic spintronic devices. We find that the magnetic properties of ferrimagnetic CoGd can be altered through ionic liquid gating. Gate voltages manipulate the opposite magnetic moments in Co and Gd sublattices and induce a giant magnetic compensation temperature change of more than 200 K in Pt/CoGd/Pt heterostructures. The electrically controlled dominant magnetic sublattice allows voltage-induced magnetization switching. Both experiments and theoretical calculations demonstrate that the significant modulations of compensation temperature are relevant to the reduced Gd moments due to the presence of hydrogen ions at positive voltages as well as the enhanced Co moments and reduced Gd moments due to the injection of oxygen ions at negative voltages. These findings expand the possibilities for all-electric and reversible magnetization control in the field of spintronics.

Electric-Field Control of Perpendicularly Magnetized Ferrimagnetic Order and Giant Magnetoresistance in Multiferroic Heterostructures

“…While net magnetization is parallel to the magnetic field, the orientations of TM and RE moments are reversed in the two states, leading to the perpendicular switching of ferrimagnetic order. Recent advances show that the magnetic compensation can be tuned by ionic migration, − mechanical stress and piezoelectric strain . The reversible switching of ferrimagnetic order with strong PMA has been demonstrated in CoGd, mediated by the voltage-driven hydrogen migration .…”