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arXiv · 1709.00910

Full angular dependence of the spin Hall and ordinary magnetoresistance in epitaxial antiferromagnetic NiO(001)/Pt thin films

Lorenzo Baldrati·Andrew Ross·Tomohiko Niizeki·Christoph Schneider·Rafael Ramos·Joel Cramer·Olena Gomonay·Mariia Filianina·Tatiana Savchenko·Daniel Heinze·Armin Kleibert·Eiji Saitoh·Jairo Sinova·Mathias Kläui
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Abstract

We report the observation of the three-dimensional angular dependence of the spin Hall magnetoresistance (SMR) in a bilayer of the epitaxial antiferromagnetic insulator NiO(001) and the heavy metal Pt, without any ferromagnetic element. The detected angular-dependent longitudinal and transverse magnetoresistances are measured by rotating the sample in magnetic fields up to 11 T, along three orthogonal planes (xy-, yz- and xz-rotation planes, where the z-axis is orthogonal to the sample plane). The total magnetoresistance has contributions arising from both the SMR and ordinary magnetoresistance. The onset of the SMR signal occurs between 1 and 3 T and no saturation is visible up to 11 T. The three-dimensional angular dependence of the SMR can be explained by a model considering the reversible field-induced redistribution of magnetostrictive antiferromagnetic S- and T-domains in the NiO(001), stemming from the competition between the Zeeman energy and the elastic clamping effect of the non-magnetic MgO substrate. From the observed SMR ratio, we estimate the spin mixing conductance at the NiO/Pt interface to be greater than $2\times10^{14}$ $Ω^{-1}$ $m^{-2}$. Our results demonstrate the possibility to electrically detect the Néel vector direction in stable NiO(001) thin films, for rotations in the xy- and xz- planes. Moreover, we show that a careful subtraction of the ordinary magnetoresistance contribution is crucial to correctly estimate the amplitude of the SMR.

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Lorenzo Baldrati, Andrew Ross, Tomohiko Niizeki, Christoph Schneider, Rafael Ramos, Joel Cramer, Olena Gomonay, Mariia Filianina, Tatiana Savchenko, Daniel Heinze, Armin Kleibert, Eiji Saitoh, Jairo Sinova, Mathias Kläui. 2021-06-24. Full angular dependence of the spin Hall and ordinary magnetoresistance in epitaxial antiferromagnetic NiO(001)/Pt thin films. https://doi.org/10.1103/physrevb.98.024422

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