講演情報
[10p-PB3-2]Large anomalous Nernst effect and magnetic anisotropy in co-sputtered tetragonal Fe2PtGa Heusler thin films
〇(PC)Nanhe Kumar Gupta1, B Bairagya1,2, W Zhou1, Y Sakuraba1,2 (1.NIMS, 2.U Tsukuba)
キーワード：
Distorted tetragonal Heusler alloy、Anomalous Hall and Nernst effect、Magnetic thin film
Tetragonally distorted Heusler compounds provide a fertile platform for studying spin-orbit-coupled electronic states, magneto crystalline anisotropy, and Berry-curvature-driven transverse transport. Although several Fe-based tetragonal Heusler compounds have been theoretically proposed [1-3], their experimental realization in thin-film and the clarification of their anomalous Hall and anomalous Nernst responses remain largely unexplored. Here, we report the first experimental realization of co-sputtered, (001)-textured tetragonal Fe2PtGa Heusler thin films and systematically investigate their anomalous Hall and anomalous Nernst effects. Structural analysis confirms the formation of a tetragonally distorted Heusler phase with strong (001) texture Fig. 1 (a). Interestingly, despite the tetragonal distortion, Fe2PtGa exhibits an in-plane magnetic easy axis (Fig. 1(b)) with a negative magnetic anisotropy constant ( MJ m-3) distinguishing it from conventional -type tetragonal systems that typically favor perpendicular magnetic anisotropy. The films exhibit a large anomalous Hall conductivity of 344 S cm-1 at 2 K (Fig. 1(c)), anomalous Nernst conductivity ~ 1.3 A m-1 K-1 and anomalous Nernst thermopower ~ 1.8 microV K-1 at 300K. These values are significantly higher than those reported for many Fe, Co, and Mn-based Heusler and binary alloy systems. Scaling analysis suggests that the anomalous Hall and anomalous Nernst effects are predominantly governed by an intrinsic Berry-curvature mechanism. These findings establish tetragonal Fe2PtGa as a promising Heusler for Berry-curvature-driven spintronic and thermoelectric functionalities.This work was supported by JST ERATO (No. JPMJER2201)[1] S.V. Faleev, et al. Phys. Rev. Appl. 7, 034022 (2017). [2] Y.I. Matsushita, et al. J. Phys. D: Appl. Phys. 50, 095002 (2017). [3] E. Xiao et al. Acta Mater. 29, 121312 (2025).