Interrelationship between grain size-induced and strain-induced broadening of X-ray diffraction profiles: What we can learn about nanostructured materials?

The two main mechanisms that cause the broadening of X-ray diffraction profiles in polycrystalline materials, i.e. those due to finite grain size and local strain inhomogeneities, are usually considered independently. In this paper, we discuss the potential interrelationship between them and propose a phenomenological equation which links the dispersion of strain distribution to grain size via the width of distorted regions near grain boundaries and the lattice disorder therein. The developed approach is applied to characterize crystallization processes in Gd-doped ceria films.