[24p-F407-1~17] 22.1 Joint Session M "Phonon Engineering"

[24p-F407-13] Control on electrical and thermal conductivities for switching-mirror films by gas-chromic reactions

〇Yuzo Shigesato¹, Kosuke Sugimoto¹, Hiroki Yagi¹, Makoto Kashiwagi¹, Yuichiro Yamashita², Takashi Yagi², Naoyuki Taketoshi² (1.Aoyama Gakuin Univ., 2.AIST)

Keywords:switchable mirror materials, gasochromism, thermal switch

The switchable mirror materials can change between semiconductor (transparent) and metallic (mirror) states reversibly by hydrogenation and dehydrogenation, respectively. Therefore, drastic changes in the thermal conductivity can be expected. There are two ways as the switching methods. One is the gas chromic method, in which the films are directly hydrogenates using hydrogen gas, and the another is the electrochemical proton-intercalation (electrochromic method). We have tried the in-situ optical, electrical, structural and thermal properties of Y-Mg and Ni-Mg alloy films in the specially designed chambers using an Ar-H₂ gas (the gasochromic method). All the films were deposited by dc magnetron sputtering, where the surfaces were coated with very thin Pd layers as the catalyst for the H-intercalation. The change of thermal conductivity measured by thermoreflectance (TDTR) method during hydrogenation almost reached an order of magnitude.