Thin Cr₂O₃ Films for Magnetoelectric Data Storage Deposited by Reactive E-beam Evaporation

Abstract

Magnetoelectric materials are proposed for use in magnetic memory applications. The main idea of the Magnetoelectric Random Access Memory (MERAM) is to enable electrical data writing in a magnetoelectric antiferromagnet, while the principle of the magnetoresistive data reading remains. As a possible medium for magnetoelectric data storage Cr ₂ O ₃ is proposed. Thin films of Cr ₂ O ₃ have been grown on a [0001] sapphire substrate by reactive e-beam evaporation of Cr ₂ O ₃ in an O ₂ atmosphere. The out-of plane orientation of the thin Cr ₂ O ₃ films and the chemical environment of Cr ³⁺ ions are evidenced by X-Ray diffractometry and absorption spectroscopy. Surface characterization has been done by atomic force microscopy. At decreasing temperature the conductivity shows an exponentional decrease, which is probably due to hopping via small amounts of Cr ₃ O ₄ .

Acknowledgments

This work was supported by DFG through SFB 491 and by the European Community within STREP NMP3-CT-2006-032616 (MULTICERAL). Special thanks are due to U. von Hörsten and M. Aderholz for X-ray diffraction measurements and technical support, respectively. Part of this work was performed at the Surface/Interface Microscopy (SIM) beamline of the Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland.