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

Antiferromagnets have attracted growing attention owing to their intriguing characteristics and promising applications in the field of spintronics. In this work, the antiferromagnetic attribute of single crystallin ${L1}_{0}\phantom{\rule{0.16em}{0ex}}\mathrm{MnPd}$ films epitaxially grown on MgO(001) substrates is proven by the exchange bias observed in ${L1}_{0} \mathrm{MnPd}/{\mathrm{Ni}}_{81}{\mathrm{Fe}}_{19}$ bilayers. The N\'eel vector in ${L1}_{0}\phantom{\rule{0.16em}{0ex}}\mathrm{MnPd}$ films is verified to be aligned along the $c$ axis by magnetoresistance measurements in longitudinal, transverse, and polar geometries of the external magnetic field. Moreover, the anomalous Hall effect is observed to become weak with increasing MnPd film thickness, indicating the existence of uncompensated magnetic moments on the surface and the collinear spin structure of ${L1}_{0}\phantom{\rule{0.16em}{0ex}}\mathrm{MnPd}$ films. 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 govern magnetotransport properties of ${L1}_{0}\phantom{\rule{0.16em}{0ex}}\mathrm{MnPd}$ films.