Magnetotransport characterization of spin structure and uncompensated magnetic moments in L10 MnPd (001) films

Antiferromagnets (AFs) have been attracting growing attention due to their advantages of multiple attractive properties, such as the absence of stray fields, immunity to external magnetic fields, and ultrafast terahertz dynamics. The spin structure and uncompensated moments on the AF surface play a critical role in manipulating the functional performance of AF spintronic devices. In this work, high-quality L10 MnPd(001) single crystal films were epitaxially grown on MgO(001) substrates. The antiferromagnetic attribute of L10 MnPd films is proven by the exchange bias observed in L10 MnPd/NiFe bilayers. The spin structure and the uncompensated magnetic moments in L10 MnPd(001) epitaxial films have been characterized directly by magnetoresistance measurements in various geometries and anomalous Hall effect, respectively. The Néel vector is identified to be perpendicular to the ab plane. Finally, exhibiting an anomaly at low temperatures, the sheet resistivity consists of the square and logarithmic temperature dependencies, due to magnon-electron scattering and an analogous orbital two-channel Kondo effect, respectively. Of most importance, the uncompensated magnetic moments are found to have a significant impact on the magnetotransport properties of L10 MnPd films.