research papers
The incorporation of hydrogen normally results in degradation when applied to metals. In this diffraction study, however, improvement of the film structure, such as in-plane grain growth, lattice defect removal and texture enhancement, was observed in a (111)-textured palladium thin film during hydrogen loading and unloading cycles. Accordingly, diffraction stress analysis was performed to investigate the evolution mechanism. It was found that the formation of the β phase during the α-to-β phase transformation occurred at the same in-plane stress present in the α phase, and vice versa. This suggests that the cyclic α–β grain boundary motion during the transformation occurred mainly along the in-plane direction, contributing to the film structure evolution.
Keywords: hydrogen; palladium; diffraction stress analysis; in situ X-ray diffraction; structure evolution.
Supporting information
Portable Document Format (PDF) file https://doi.org/10.1107/S1600576717012638/nb5202sup1.pdf |