Topochemical Fluoride Exchange Reaction with Anionic Electrons toward Fluoride-Ion Conduction in Layered Ba _{2– x} A _x NF _{1– x} (A = Na, K)

[1 ]Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo, Kyoto 606-8501, Japan

[2 ]Institute of Materials Innovation, Institutes of Innovation for Future Society, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan

[3 ]Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai, Ibaraki 319-1106, Japan