Speaker
Description
Metallic hydrides (MeHx) have proven in the last decade highly attractive to the scientific community as room-temperature superconductors and, due to their composition (a controllable mixture of heavy and light elements), also as potential materials for solid targets for high power laser experiments. Computational methods were used to study the structure and physical properties of several hydrides from Me-H systems (with Me=Cr and Pd) via density functional theory (DFT) in order to observe the superconducting phase originating from the strong electron-phonon coupling and high-frequency modes provided by hydrogen embedded in metallic interstitial sites. In order to determine the stable structures, the formation enthalpy as a function of stoichiometry and pressure was investigated using an efficient structure prediction software (CALYPSO), while physical properties were determined using an all electron linearized augmented plane wave code (ELK). The computational data showed that most of the studied hydrides feature a closely-packed metal lattices, with hydrogen filling interstitial sites, while electron-phonon coupling calculations showed that, when superconducting, these phases are phonon-mediated superconductors. Experimental results of hydride films fabricated by RF sputtering, including epitaxial PdH thin films obtained for the first time by a physical deposition method, will also be presented, with focus on hydride phase stability.
