X-Ray Diffraction Study on a Superionic Conductor: α-Ag2Se

An oscillatory background and Debye lines of α-Ag 2 Se which has so-called averaged structure were studied by X-ray diffraction experiments. The diffuse background was analyzed by assuming a liquid-like distribution of Ag atoms and the pair distribution function g Ag-Ag ( r ) was obtained. The calculated intensities of Debye lines by the liquid-like Ag distribution model agreed qualitatively with the observed intensities. Therefore, it is not necessary for Ag atoms to be confined to 42 sites which were introduced by Rahlfs. A mean potential U Ag ( r ) of Ag atoms was calculated from the mean density distribution of Ag atoms ρ Ag ( r ), and was related to an asymmetric thermal vibration of Ag atoms in α-Ag 2 Se.