Robust isothermal electric control of exchange bias at room temperature

Authors

Xi He, University of Nebraska-Lincoln
Ning Wu, University of Nebraska-Lincoln
Anthony N. Caruso, University of Missouri-Kansas CityFollow
Elio Vescovo, Brookhaven National LaboratoryFollow
Kirill D. Belashchenko, University of Nebraska-LincolnFollow
Peter A. Dowben, University of Nebraska-LincolnFollow
Christian Binek, University of Nebraska-LincolnFollow

Date of this Version

2010

Document Type

Article

Citation

Nature Materials Vol. 9 (July 2010)

Comments

U.S. Government Work

Abstract

Voltage-controlled spin electronics is crucial for continued progress in information technology. It aims at reduced power consumption, increased integration density and enhanced functionality where non-volatile memory is combined with highspeed logical processing. Promising spintronic device concepts use the electric control of interface and surface magnetization. From the combination of magnetometry, spin-polarized photoemission spectroscopy, symmetry arguments and first-principles calculations, we show that the (0001) surface of magnetoelectric Cr₂O₃ has a roughness-insensitive, electrically switchable magnetization. Using a ferromagnetic Pd/Co multilayer deposited on the (0001) surface of a Cr₂O₃ single crystal, we achieve reversible, room-temperature isothermal switching of the exchange-bias field between positive and negative values by reversing the electric field while maintaining a permanent magnetic field. This effect reflects the switching of the bulk antiferromagnetic domain state and the interface magnetization coupled to it. The switchable exchange bias sets in exactly at the bulk Néel temperature.