Irradiation tolerance of spin-driven thermoelectric device against gamma-rays

スピン駆動熱電素子のガンマ線に対する照射耐性

家田 淳一   ; 岡安 悟  ; 武山 昭憲*; 針井 一哉*; 大島 武*; 石田 真彦*; 齊藤 英治

Ieda, Junichi; Okayasu, Satoru; Takeyama, Akinori*; Harii, Kazuya*; Oshima, Takeshi*; Ishida, Masahiko*; Saito, Eiji

We investigate irradiation tolerance against gamma-rays of a prototypical spin-driven thermoelectric (STE) device based on YFeO/Pt heterostructures. The past study has proved that the STE device was rad-hard against the gamma-irradiation dose up to 0.3 MGy. In this study, we assess the radiation hardness in severer environments, such as higher dose levels, higher ambient temperatures, and water steam, assuming the future RTG usage near the spent nuclear fuel storage. We show that the YFeO/Pt STE device has tolerance to irradiation of gamma rays up to 0.9 MGy even at 150 C. On the other hand, we observe the performance degradation of the STE device by the gamma-irradiation under the water steam. From a control experiment without gamma-rays, the irradiation is irrelevant, and the damage is caused solely by the water steam effect. To avoid the damage, it is found that the thicker Pt film (10 nm) in the STE device is effective. Therefore, it was clarified that the STE device has fundamentally high resistance to gamma rays.