Beryllium Polyhydride Be4H8(H2)2 Synthesized at HP/HT

TL;DR

This study reports the synthesis and characterization of a novel beryllium polyhydride phase, Be4H8(H2)2, formed under high pressure and temperature, revealing its structure, stability, and potential as a metastable phase in the Be-H system.

Contribution

The paper presents the first synthesis and detailed structural analysis of Be4H8(H2)2 using experimental and computational methods under high-pressure conditions.

Findings

Be4H8(H2)2 crystallizes in P6_3/mmc structure

Stable between 4 GPa and 14 GPa at room temperature

Identified as a metastable phase via ab-initio calculations

Abstract

We report the XRD and Raman scattering measurements in combination with DFT calculations that reveal the formation of beryllium polyhydride Be4H8(H2)2 by laser heating Be/H2 mixture to above 1700 K at pressures between 5 GPa and 8 GPa. The Be4H8(H2)2 crystallizes in a P6_3/mmc structure and consists of corner-sharing BeH4 tetrahedrons and H2 molecules that are in an interstitial site. The Be4H8(H2)2 is stable at least to 14 GPa on compression and stable down to 4 GPa at room temperature. Our ab-initio calculations suggest that the Be4H8(H2)2 is a meta-stable phase of Be-H system.