Anisotropic magnetoresistance and nontrivial spin Hall magnetoresistance in Pt/α−Fe2O3 bilayers

Magnetic proximity effect has only been conclusively observed in ferromagnet-based systems. We report the observation of anomalous Hall effect and angular-dependent anisotropic magnetoresistance in Pt on antiferromagnetic <math><mrow><mi>Pt</mi><mo>/</mo><mi>α</mi><mtext>–</mtext><mi mathvariant='normal'>F</mi><msub><mi mathvariant='normal'>e</mi><mn>2</mn></msub><msub><mi mathvariant='normal'>O</mi><mn>3</mn></msub></mrow></math> (0001) epitaxial films at 10 K, which provide evidence for the magnetic proximity effect. The Neel order of <math><mrow><mi>Pt</mi><mo>/</mo><mi>α</mi><mtext>–</mtext><mi mathvariant='normal'>F</mi><msub><mi mathvariant='normal'>e</mi><mn>2</mn></msub><msub><mi mathvariant='normal'>O</mi><mn>3</mn></msub></mrow></math> and the induced magnetization in Pt show a unique angular-dependent magnetoresistance compared with all other ferromagnetic and antiferromagnetic systems. In conclusion, a macrospin response model is established and can explain the antiferromagnetic spin configuration and all main magnetoresistance features in the <math><mrow><mi>Pt</mi><mo>/</mo><mi>α</mi><mtext>–</mtext><mi mathvariant='normal'>F</mi><msub><mi mathvariant='normal'>e</mi><mn>2</mn></msub><msub><mi mathvariant='normal'>O</mi><mn>3</mn></msub></mrow></math> bilayers.