Magnetoresistance Effects in the Metallic Antiferromagnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:msub><mml:mi>Mn</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi>Au</mml:mi></mml:math>
S. Yu. Bodnar, Y. Skourski, O. Gomonay, J. Sinova, M. Kläui, M. Jourdan
Abstract
In antiferromagnetic spintronics, it is essential to separate the resistance modifications of purely magnetic origin from other effects generated by current pulses intended to switch the N\'eel vector. We investigate the magnetoresistance effects resulting from magnetic-field-induced reorientations of the staggered magnetization of epitaxial antiferromagnetic ${\mathrm{Mn}}_{2}\mathrm{Au}(001)$ thin films. The samples are exposed to 60-T magnetic field pulses along different crystallographic in-plane directions of ${\mathrm{Mn}}_{2}\mathrm{Au}(001)$, while their resistance is measured. For the staggered magnetization aligned via a spin-flop transition parallel to the easy [110] direction, an anisotropic magnetoresistance of $\ensuremath{\simeq}\ensuremath{-}0.15\mathrm{%}$ is measured. In the case of a forced alignment of the staggered magnetization parallel to the hard [100] direction, evidence for a larger anisotropic magnetoresistance effect is found. Furthermore, transient resistance reductions of $\ensuremath{\simeq}1\mathrm{%}$ are observed, which we associate with the annihilation of antiferromagnetic domain walls by the magnetic field pulses.