Exploring the Phase Diagram of the Palladium Hydrogen System using Bragg Coherent Diffraction Imaging

The goal of this study is to observe the structural evolution of single palladium nanocrystals during hydrogen absorption and desorption in rarely explored regions of the phase diagram. The Pd-H system is extremely interesting for its capability to uptake large amount of hydrogen into interstitial sites with an accompanying lattice expansion. There exist several phenomena that have not been observed in single nanocrystals such as high temperature and pressure absorption, and absorption in the supercritical phase. As well as more exotic phenomena such as spinodal decomposition that is posited to exist in small single crystals. Using Bragg Coherent Diffraction Imaging (BCDI) we are able to follow in-situ the evolution of the internal and surface strain in individual nanoparticles.