Probing boundary magnetization with spin Hall magnetoresistance in high T_N boron-doped magnetoelectric Cr₂O₃

Voltage controlled magnetization is a promising route for next-generation low-energy magnetic recording and logic devices. Utilizing magnetoelectric Cr₂O₃ based heterostructures, electric control of ferromagnetic exchange bias has been achieved up to the bulk Néel temperature. Recently spin Hall magnetoresistance has been shown to be present in Cr₂O₃ Pt bilayers, potentially providing a readout mechanism of the antiferromagnetic order parameter which avoids the need for a ferromagnet. In this study we combine this novel readout mechanism with the technique of boron-doping the Cr₂O₃ which increases the Néel temperature up to 400 K. Using a process of magnetoelectric annealing, spin Hall magnetoresistance in boron-doped Cr₂O₃ films is examined for the first time, with significant implications for future spintronic devices.