Probing Interfacial Magnetism in Non-Collinear Antiferromagnetic SmFeO₃ Single Crystal via Spin Hall Magnetoresistance

Effectively detecting the magnetization of antiferromagnetic materials and manipulating antiferromagnetic moments through all-electrical methods remain fundamental challenges. The spin Hall magnetoresistance in noncollinear antiferromagnetic systems present a promising avenue to overcome above obstacles. In this work, SmFeO3/Pt and SmFeO3/Cu/Pt heterostructures based on polished SmFeO3 single crystals were fabricated to probe the interfacial magnetic moment. The inserted Cu layer serves to eliminate magnetic proximity effects for SmFeO3/Pt interface. The magnetotransport and magnetic measurements in SmFeO3/Pt heterostructures indicate that both the spin Hall magnetoresistance and the magnetization exhibit a decrease as the temperature drops below 150 K, attributed to the emergence of magnetic ordering in Sm sublattice. The correlation in temperature dependence between the SMR and magnetization indicates that spin Hall magnetoresistance is a sensitive probe for the microscopic magnetic moments at the interfaces of antiferromagnetic insulators/heavy metal. Comparative studies on SmFeO3/Cu/Pt heterostructures show that inserted Cu layer modifies the magnetic anisotropy of interfacial moments. Furthermore, anomalous Hall effect in SmFeO3/Pt heterostructures exhibit sign reversal near 80 K, attributed to the competition between magnetic proximity-induced anomalous Hall effect and spin Hall effect-induced anomalous Hall effect. This study introduces the detection of interfacial magnetic moment in SmFeO3 single crystals via spin transport measurements.