  In this work, the investigation of magnetic proximity effect was extended to
Ta which has been reported to have a negative spin Hall angle.
Magnetoresistance and Hall measurements for in-plane and out-of-plane applied
magnetic field sweeps were carried out at room temperature. The size of the MR
ratio observed (~10-5) and its magnetization direction dependence are similar
to that reported in Pt/YIG, both of which can be explained by the spin Hall
magnetoresistance theory. Additionally, a flip of magnetoresistance polarity is
observed at 4 K in the temperature dependent measurements, which can be
explained by the magnetic proximity effect induced anisotropic
magnetoresistance at low temperature. Our findings suggest that both magnetic
proximity effect and spin Hall magnetoresistance have contribution to the
recently observed unconventional magnetoresistance effect.
