結晶構造の不規則性に基づくX線の散漫散乱について〔2〕

概要

論文の詳細を見る
A general theory of the propagation of orders, an extension of Zernike's theory on the same problem, is developed to obtain the intensity formula of scattered x-ray by a partially ordered crystal. The intensity of the diffuse scattering, which was denoted by J (b) in Part i of this paper, can now be expresed in the form : J (b) =Σ _??_ where λi are the eigenvalues of a matrix B whose elements are determined from the molecular interaction between a lattice point and its first neighbours and from the path differences of the x-ray wave scattered at them. mii are the diagonal elements of another matrix M. As an illustration of the method, the diffuse scattering from a face centered lattice consisting of diatomic molecules, in which molecular axes are order-disorderly arranged among four directions ( [111] and its equivalents), is considered. A theory of the phase transition of this lattice is also given. This example is presumably applicable to the low temperature form of N2 (ordered state) and the high temperature form of NaCNN or KCN (disordered state) . In the last section a general discussion of the relation between the diffuse scattering and the phase transition is developed; it is pointed out that the diffuse scattering should show a remarkable temperature dependence near the transition point.
日本結晶学会の論文