<i>Ab initio</i> study of metastable occupation of tetrahedral sites in palladium hydrides and its impact on superconductivity

Abstract

Palladium hydride is one of the rare examples of superconducting hydrides at ambient pressure, exhibiting a critical temperature of 10 K in its equilibrium structure, with hydrogen atoms occupying octahedral interstitial sites of the palladium fcc lattice. Making use of $a\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ calculations considering quantum anharmonic lattice effects, the authors show here that full or partial occupation of tetrahedral sites is possible in metastable structures, but that their superconducting critical temperature is lower than the equilibrium case with full octahedral occupation.

Topics & Concepts