Physical interpretation of Stephens' phenomenological parameters for anisotropic microstrain broadening in cubic systems.

Both the Stephens phenomenological model and the modified Williamson-Hall (mWH) plot analysis address the microstrain-dependent anisotropic peak broadening observed in diffraction patterns. The data analysis strategies of both methods rely on the anisotropic nature of crystalline materials and the quartic form of reflection indices (hkl). Despite these similarities, the results of the two methods are not directly comparable: the Stephens approach is phenomenological, whereas the mWH method is based on the characteristic dislocation parameters for determining microstructural features (size-strain). This study aims to bridge that gap. A simple procedure is proposed to extract microstructural quantities - equivalent to those obtained by the mWH method - using the Stephens phenomenological approach. Furthermore, a microscopic interpretation of Stephens' phenomenological parameters is presented in terms of the nature of dislocations in cubic symmetry. The applicability of this procedure is demonstrated for cubic systems and illustrated with examples.