Crystal Structure and Phase Transition of Some Metallic Halides : IV On the Anomalous Structure of α-AgI

概要

論文の詳細を見る
Intensities of X-ray diffraction from α-AgI at various temperatures were measured in the absolute scale by using a G-M counter spectrometer with the crystal monochromated Cu Kα radiation. Measurements of the specific heat and the thermal expansion were also performed. A drastic temperature dependence of the intensities of Debye lines and the presence of a comparatively strong diffuse buckground were detected. The observed intensities of the Debye lines could be explained well by the disordered structure model (or the "averaged structure") proposed by Strock (Z. Physik. Chem., B31 (1936) 132.), assuming fairly large Debye factors for silver and iodine atoms. The intensity of the diffuse background from such an averaged structure was calculated in the similar way as in the case of binary alloys having short range order, assuming appropriate probability functions for the presence of atoms in different sites. It was confirmed that the intensity curves of the diffuse background measured at 250° and 400℃ were in fair agreements with the theoretical ones. The nature of the "averaged structure" having the random arrangement of silver atoms and the origin in of the large displacements of atoms from their equilibrium positions were discussed.
社団法人日本物理学会の論文
1957-04-05