Magnetization of Graphane by Dehydrogenation

TL;DR

This paper investigates how creating hydrogen vacancies in graphane induces local magnetic moments, with the potential for applications in data storage and spintronics, based on first-principles calculations.

Contribution

It provides a detailed analysis of magnetic properties of hydrogen vacancy domains in graphane, highlighting the influence of domain size, geometry, and hydrogen arrangement.

Findings

Vacancy domains can have sizable net magnetic moments.

Hydrogen atom relocation at the opposite side affects spin pairing.

Size and ordering of magnetic moments are tunable for applications.

Abstract

Each single hydrogen vacancy created at the surface of graphane gives rise to a local unpaired spin. For domains of hydrogen vacancies the situation is, however complex and depends on the size and geometry of domains, as well as whether the domains are single- or double-sided. In single-sided domains, hydrogen atoms at the other side are relocated to pair the spins of adjacent carbon atoms by forming pi-bonds. Owing to the different characters of exchange coupling in different ranges and interplay between unpaired spin and the binding geometry of hydrogen, vacancy domains can attain sizable net magnetic moments. Our results based on the first-principles calculations suggest that the size and ordering of magnetic moments of hydrogen vacancy domains with thin walls can be used for future data storage and spintronics applications.