Thermal diffuse X-ray scattering for small samples and small coherent scattering domains

The influences of sample size and mosaic block size upon X-ray thermal diffuse scattering have been investigated. Surface and edge vibrational modes were incorporated into the Debye spectrum. Two additional terms, which depend on the surface/volume and edge-length/volume ratios, appear therefore in the expression for the scattered intensity. The TDS contributions of the volume and surface terms to the integrated Bragg intensity are calculated numerically.