Proton mobility in metallic copper hydride from high-pressure nuclear magnetic resonance
Thomas Meier, Florian Trybel, Giacomo Criniti, Dominique Laniel, Saiana Khandarkhaeva, Egor Koemets, Timofey Fedotenko, Konstantin Glazyrin, Michael Hanfland, Maxim Bykov, Gerd Steinle‐Neumann, Natalia Dubrovinskaia, Leonid Dubrovinsky
Abstract
The atomic and electronic structures of ${\mathrm{Cu}}_{2}\mathrm{H}$ and CuH have been investigated by high-pressure nuclear magnetic resonance spectroscopy up to 96 GPa, X-ray diffraction up to 160 GPa, and density functional theory-based calculations. Metallic ${\mathrm{Cu}}_{2}\mathrm{H}$ was synthesized at a pressure of 40 GPa, and semimetallic CuH at 90 GPa, found stable up to 160 GPa. For ${\mathrm{Cu}}_{2}\mathrm{H}$, experiments and computations show an anomalous increase in the electronic density of state at the Fermi level for the hydrogen $1s$ states and the formation of a hydrogen network in the pressure range 43--58 GPa, together with high $^{1}\mathrm{H}$ mobility of $\ensuremath{\sim}{10}^{\ensuremath{-}7}\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{2}/\mathrm{s}$. A comparison of these observations with results on FeH suggests that they could be common features in metal hydrides.