Hydrogen-doped cubic diamond and the crystal structure of n-diamond

TL;DR

This study uses first principles calculations to analyze hydrogen-doped diamond, revealing that low hydrogen concentrations stabilize the structure and match experimental data, suggesting n-diamond is likely hydrogen-doped.

Contribution

The paper provides a detailed first-principles analysis of hydrogen-doped diamond's structure, linking hydrogen concentration to stability and experimental properties of n-diamond.

Findings

H-doped diamond is mechanically stable below 19 at.% hydrogen.

At around 4 at.% hydrogen, properties match experimental n-diamond.

Hydrogen doping likely explains the structure of n-diamond.

Abstract

To understand the crystal structure of n-diamond, a hydrogen-doped (H-doped) diamond model has been investigated using first principles calculations. In particular, hydrogen concentration dependent elastic constants and lattice parameters for the H-doped diamond have been analyzed. Our results indicate that when the hydrogen concentration is less than 19 at.%, the H-doped diamond is mechanically stable. When the hydrogen concentration is about 4 at.%, the optimized lattice parameter, simulated XRD pattern and electronic properties for the H-doped diamond all agree well with the corresponding experimental values of n-diamond. The results imply that the n-diamond is likely to be an H-doped diamond.