[18a-A24-1~9] 13.2 Exploratory Materials, Physical Properties, Devices

9:00 AM - 9:15 AM JST(12:00 AM - 12:15 AM UTC)

[18a-A24-1] Exploration of growth conditions for epitaxial Mg₃Bi₂ thin films on c-Al₂O₃ substrates

〇(D)Akito Ayukawa¹, Takeru Kuriyama¹, Haruhiko Udono¹, Shunya Sakane¹ (1.Ibaraki Univ.)

Keywords:

Thermoelectric materials,Mg3Bi2,Epitaxial growth

Thin-film thermoelectric materials are expected to be applied to compact stand-alone power supplies using familiar waste heat, and Mg₃Bi₂-based materials have attracted particular attention for their high performance near room temperature due to their low thermal conductivity. However, epitaxial Mg₃Bi₂ thin films have been rarely reported and the growth conditions have not been discussed until now. this study, we explore and establish growth conditions for epitaxial Mg₃Bi₂ thin films by molecular beam epitaxy for high-performance thermoelectric material applications. After growth, the RHEED figures showed streaks, confirming the epitaxial growth of the Mg₃Bi₂ thin film. Cross-sectional observation by SEM showed that the film thickness was about 150 nm. XRD patterns show that c-plane oriented Mg₃Bi₂ thin films were obtained. We found that Mg₃Bi₂ thin films were not formed at a substrate temperature of 500 °C, indicating that Mg₃Bi₂ is highly susceptible to re-evaporation.