Li diffusion in NaTl-type intermetallic compound LiGa observed by Li short-lived radiotracer

Sugai, Hiroyuki; Sataka, Masao; Okayasu, Satoru  ; Ichikawa, Shinichi; Nishio, Katsuhisa   ; Mitsuoka, Shinichi; Nakanoya, Takamitsu  ; Osa, Akihiko  ; Sato, Tetsuya   ; Hashimoto, Takashi; Jeong, S.-C.*; Katayama, Ichiro*; Kawakami, Hirokane*; Watanabe, Yutaka*; Ishiyama, Hironobu*; Imai, Nobuaki*; Hirayama, Yoshikazu*; Miyatake, Hiroari; Hashimoto, Takanori*; Yahagi, Masahito*

Non-destructive and on-line Li diffusion experiments in Li ionic conductors are conducted using the short-lived -emitting radiotracer of Li. The radiotracers produced as an energetic and pulsed ion beam from TRIAC (Tokai Radioactive Ion Accelerator Complex) are implanted into a structural defect mediated Li ionic conductor of NaTl-type intermetallic compounds -LiGa. The diffusion coefficients obtained for -LiGa with Li content of 43-54 at.% at room temperature are discussed in terms of the interaction between Li-ion and the structural defects in the specimen, compared with the case of -LiAl and -LiIn. The nonlinear Li-content dependency of Li diffusion coefficients for -LiGa suggests that the Li diffusion with Li-deficient region is obstructed by the defect complex composed of vacancies at the Li sites.