Proton mobility in metallic copper hydride from high-pressure nuclear magnetic resonance

The atomic and electronic structures of Cu2H 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 Cu2H was synthesized at a pressure of 40 GPa, and semimetallic CuH at 90 GPa, found stable up to 160 GPa. For Cu2H, 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 H-1 mobility of similar to 10(-7) cm(2)/s. A comparison of these observations with results on FeH suggests that they could be common features in metal hydrides.
Funding Agencies|German Research Foundation (Deutsche Forschungsgemeinschaft, DFG)German Research Foundation (DFG) [DU 954/11-1, DU 393/13-1, DU 393/9-2, ME 5206/3-1, STE 1105/13-1, FOR 2440]; Federal Ministry of Education and Research, Germany (BMBF)Federal Ministry of Education & Research (BMBF) [05K19WC1]; Alexander von Humboldt FoundationAlexander von Humboldt Foundation; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]