Journal Article

Anisotropic magnetoresistance in an antiferromagnetic semiconductor

Suresha, S., Marti, X., Rayan-Serrao, C., Shick, A. B., Yi, D., Fontcuberta, J., Ramesh, R., Chu, J. H., Liu, J., Železný, J., Jungwirth, T., Fina, I.

2014

Overview

Recent studies in devices comprising metal antiferromagnets have demonstrated the feasibility of a novel spintronic concept in which spin-dependent phenomena are governed by an antiferromagnet instead of a ferromagnet. Here we report experimental observation of the anisotropic magnetoresistance in an antiferromagnetic semiconductor Sr 2 IrO 4 . Based on ab initio calculations, we associate the origin of the phenomenon with large anisotropies in the relativistic electronic structure. The antiferromagnet film is exchange coupled to a ferromagnet, which allows us to reorient the antiferromagnet spin-axis in applied magnetic fields via the exchange spring effect. We demonstrate that the semiconducting nature of our AFM electrode allows us to perform anisotropic magnetoresistance measurements in the current-perpendicular-to-plane geometry without introducing a tunnel barrier into the stack. Temperature-dependent measurements of the resistance and anisotropic magnetoresistance highlight the large, entangled tunabilities of the ordinary charge and spin-dependent transport in a spintronic device utilizing the antiferromagnet semiconductor. The change in the electrical properties of a ferromagnetic under the influence of a magnetic field depends strongly on field orientation. Marti et al. now show that this so-called anisotropic magnetoresistance is also evident in antiferromagnetic semiconductors, making them useful in spintronics.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/301/119/1000 / 639/301/119/997 / 639/766/25 / Humanities and Social Sciences / Magnetic fields / multidisciplinary / Science / Science (multidisciplinary)