Proton Conducting Properties of Layered Metal Phosphate Hydrates
The proton conducting properties of layered metal phosphates hydrates (M (HPO4)2·nH2O (M = Sn, Ti, Zr), MPs) were examined under various humidities at 20−150°C. SnP showed a high conductivity of more than 10-2 S cm-1 under saturated water vapor pressure and a weak humidity dependence of its conductivity at 150°C. The hydrated water content (n) of ZrP was approximately stable at 1 in a wide humidity range of more than 20% at 150°C. The n of SnP varied more widely than that of ZrP; however, the conductivity of SnP remained high even in a low-n range. The short distance between adjacent hydrated water molecules was suggested to be the reason for the high proton conductivity of SnP.
Keiichi Katayama, Kazumi Kato, Tadashi Takenaka, Masasuke Takata and Kazuo Shinozaki
Y. Kawakami and M. Miyayama, "Proton Conducting Properties of Layered Metal Phosphate Hydrates ", Key Engineering Materials, Vol. 320, pp. 267-270, 2006