Formation of transition metal hydrides at high pressures

TL;DR

This paper investigates how silane decomposes at high pressures, releasing hydrogen that forms metal hydrides, highlighting the importance of considering chemical reactions in high-pressure experiments.

Contribution

It reveals the formation of metal hydrides from silane decomposition at high pressures, identifying platinum hydride as a key phase in previous high-pressure silane studies.

Findings

Silane decomposes above 50 GPa into silicon and hydrogen.

Hydrogen reacts with metals to form metal hydrides.

High-pressure silane phases may actually be metal hydrides.

Abstract

Silane (SiH4) is found to (partially) decompose at pressures above 50 GPa at room temperature into pure Si and H2. The released hydrogen reacts with surrounding metals in the diamond anvil cell to form metal hydrides. A formation of rhenium hydride is observed after the decomposition of silane. From the data of a previous experimental report (Eremets et al., Science 319, 1506 (2008)), the claimed high-pressure metallic and superconducting phase of silane is identified as platinum hydride, that forms after the decomposition of silane. These observations show the importance of taking into account possible chemical reactions that are often neglected in high-pressure experiments.