Giant and Nonvolatile Control of Exchange Bias in Fe3GeTe2/Irradiated Fe3GeTe2/MgO Heterostructure Through Ultralow Voltage

Abstract

AbstractThe discovery of van der Waals magnets has provided a new platform for the electrical control of magnetism. Recent experiments have demonstrated that the magnetic properties of van der Waals magnets can be tuned by various gate modulations, although most of them are volatile and require gate voltages no lower than several volts. Here, the realization of nonvolatile control of exchange bias and coercive fields in Fe3GeTe2/MgO heterostructures, and the gate voltage is as low as tens of mV which is two orders of magnitude smaller than those in previous experiments is presented. The discovery of an ionic‐irradiated phase formed in Fe3GeTe2 by MgO sputtering revealed that an exchange bias effect can be obtained in this heterostructure and tuned from ≈700 to 0 Oe through voltages ranging from 5 to 20 mV. Owing to the high stability of oxidized Fe3GeTe2, the voltage‐driven oxygen incorporated into Fe3GeTe2 from the irradiated phase induces a nonvolatile magnetism modulation that can be retained after turning off the gate voltage. These findings demonstrate a methodology to modulate the magnetism of van der Waals magnets, opening new opportunities to fabricate all‐solid, long‐retention, and low‐dissipation nano‐electronic devices using van der Waals materials.