[23p-12D-1~14] 10.2 Fundamental and exploratory device technologies for spin

4:45 PM - 5:00 PM JST(7:45 AM - 8:00 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[23p-12D-12] Enhancement of anomalous Nernst effect in annealed-CoGe thin films

〇(M2)Takuya Tsujimoto¹, Takeshi Fujita², Shigenori Ueda³, Toshio Miyamachi¹, Masaki Mizuguchi¹ (1.Nagoya Univ., 2.Kochi Univ. Tech., 3.NIMS)

Keywords:

spintronics,spin caloritronics,the Anomalous Nernst effect

We investigated the anomalous Nernst effect in CoGe thin films and effect of post-annealing for ANE was investigated. CoGe thin films were fabricated by the co-sputtering method on MgO substrates at room temperature. Post-annealing was performed at temperatures ranging from 473 to 1073 K. Crystallographic structures were characterized by a transmission electron microscope (TEM). The Nernst voltage was measured by a physical property measurement system (PPMS). It was confirmed that as deposited CoGe thin films possessed columnar structures and the samples annealed at 573 - 773 K possessed island ordered phase of Co₂Ge by cross-sectional TEM images. S_xy increased in the latter series and reached up to 1.2 µV/K, which substantiates the effect of post-annealing for ANE. To investigate the mechanism of the enhancement of the ANE, we conducted hard x-ray photoelectron spectroscopy (HAXPES) and studied electronic structures of each sample.