Anomalous Nernst effect in L10 type Mn-Ga alloy thin films

L1₀ type MnGa alloy is attracting attention as materials to be applied to spintronic devices since they generally show large magnetic anisotropy, small saturation magnetization, and small Gilbert damping constant. It is known that an L1₀ type MnGa alloy thin film keeps large magnetic anisotropy with the increase of the Mn-composition even though saturation magnetization decreases. Thus, it is interesting to investigate various magnetic properties of this alloy-system. On the other hand, “spin-caloritronics”, which deals with a relationship between spin current and heat current, is getting an attracting research field. Previously, we studied a thermomagnetic phenomenon, that is, anomalous Nernst effect (ANE), of L1₀ type FePt alloy thin films, and evaluated anomalous Nernst coefficient and anomalous Nernst angle of the FePt thin film. Besides, a new-type of thermopile device using ANE was proposed to show a potential of ANE-based thermoelectric applications. In this paper, ANE of epitaxial Mn_x-Ga_1-x thin films with varied Mn-compositions (x) within the L1₀ composition range was systematically studied to explore their thermomagnetic characteristics. Moreover, anomalous Hall effects (AHE) of the films were investigated to understand the correlation of the two effects in L1 type Mn-Ga thin films.