Effect of crystal structure on diffusion broadening of Mössbauer line shape in polycrystalline samples

Abstract

Experimental observations of diffusional broadening of the Mössbauer resonance in polycrystalline solids have generally been analyzed on the basis of a liquidlike model which neglects the restriction of atomic jumps to crystallographically determined directions. A calculation based on the theoretical results of Chudley and Elliot for single crystals, averaged over all directions, shows that a substantial correction to the liquidlike result is required. Application of this correction, along with a simple assumption about the correlation factor largely eliminates the existing discrepancies between theory and experiment.