TEMPERATURE DIFFUSE SCATTERING FOR POWDER PATTERNS FROM HEXAGONAL CRYSTALS

Assuming the Brillouin zone to be spherical an expression for temperature diffuse scattering (TDS) for hexagonal powders has been derived. The expression has been based on the general equation for thermal diffuse scattering due to Born and its extension due to Begbie. For magnesium, where the Brillouin zone is approximately spherical, TDS line profiles have been calculated for 101 bar above0 and 0002 reflections. It has been found that for these reflections TDS peaks appear at the same positions as the Bragg peaks and the TDS contribution to the tails of both the line profiles is quite appreciable.