Hydrogen arranged itself at dislocations in palladium so as to form nanoscale hydrides; changing the vibrational spectra. An ab initio hydrogen potential energy model versus Pd neighbor distances permitted the prediction of the vibrational excitations for H from absolute zero up to room temperature adjacent to a partial dislocation and with strain. Using the equilibrium distribution of hydrogen with temperature, excitation spectra were predicted which explained new incoherent inelastic neutron-scattering measurements. At 0K, dislocation cores trapped H to form nanometer-sized hydrides, while increased temperature dissolved the hydrides and dispersed H throughout bulk Pd.

Nanoscale Hydride Formation at Dislocations in Palladium: ab initio Theory and Inelastic Neutron Scattering Measurements. D.R.Trinkle, H.Ju, B.J.Heuser, T.J.Udovic: Physical Review B, 2011, 83[17], 174116