Theory of the Effect of Temperature on the Reflection of X-Rays by Crystals. II. Anisotropic Crystals

In anisotropic crystals the temperature factor for the reflection of x-rays is a function of the orientation of the reflection plane. The general case of anisotropic metals is here treated by an extension of a simple method recently discussed in this journal. The complete solution is found for metals with hexagonal symmetry. The temperature factor is generally written as e^-M. The constant M is explicitly calculated for Zn and Cd (hexagonal symmetry). It is found that for these two metals M is 1.80, 1.73, respectively, as large for the reflection plane normal to the principal axis as for reflection planes parallel to the principal axis.