On the Thermal Stability of Graphone

TL;DR

This study uses molecular dynamics to analyze how hydrogen atoms migrate in graphone, revealing its very low thermal stability due to a small activation energy, which limits its practical nanoelectronic applications.

Contribution

The paper provides the first direct measurement of the temperature-dependent disordering time and activation energy for hydrogen migration in graphone.

Findings

Activation energy for hydrogen migration is approximately 0.05 eV.

Graphone exhibits extremely low thermal stability.

Hydrogen atoms readily hop at relatively low temperatures.

Abstract

Molecular dynamics simulation is used to study thermally activated migration of hydrogen atoms in graphone, a magnetic semiconductor formed of a graphene monolayer with one side covered with hydrogen so that hydrogen atoms are adsorbed on each other carbon atom only. The temperature dependence of the characteristic time of disordering of graphone via hopping of hydrogen atoms to neighboring carbon atoms is established directly. The activation energy of this process is found to be Ea=(0.05+-0.01) eV. The small value of Ea points to extremely low thermal stability of graphone, this being a serious handicap for practical use of the material in nanoelectronics.