MAGNETOELECTRIC Cr₂O₃ FOR SPINTRONIC APPLICATIONS

ABSTRACT

Magnetoelectric (ME) materials being at the same time antiferromagnetic (AF) are proposed to be used in spintronic applications, e.g. for Magnetic Random Access Memory (MRAM). The main idea considers exchange coupling to a ferromagnet at the interface of the ME material and corresponding exchange bias (EB). The proposed electric switching of the EB field has been demonstrated on systems of single Cr₂O₃ crystalline substrates covered by [Co/Pt] _n heterolayers [1]. Thin Cr₂O₃ thin films have been prepared by Molecular Beam Epitaxy (MBE) in order to be ready for downscaling. Corresponding EB systems show perpendicular EB at temperatures below T _B ≈ 265 K. As an origin of the observed difference from the single crystal behavior, the formation of Cr₂O₃ nanograins at the interface is proposed and confirmed by measurements before and after thermal annealing of the sample [1]. P. Borisov, A. Hochstrat, X. Chen, W. Kleemann, and Ch. Binek, Phys. Rev. Lett. 94 117203 (2005).

Keywords:

• Spintronics
• Magnetoelectricity
• Multiferroics
• Exchange Bias

ACKNOWLEDGMENTS

Financial support by the Deutsche Forschungsgemeinschaft via Sonderforschungsbereich 491 and by the Europen Community within STREP NMP3-CT-2006-032616 (MULTICERAL) is gratefully acknowledged. Special thanks are due to U. von Hörsten and M. Aderholz for X-ray diffraction measurements and technical support, respectively.