Magnetic impurities in graphane with dehydrogenated channels

TL;DR

This study uses density functional theory to explore how magnetic impurities like Fe behave in patterned dehydrogenated channels of graphane, revealing different magnetic responses based on channel type and width, with potential for ultrathin magnetic devices.

Contribution

It provides a detailed analysis of magnetic impurity behavior in graphane channels, highlighting differences between armchair and zigzag edges and their impact on magnetic properties.

Findings

Magnetic response varies significantly between armchair and zigzag channels.

Fe impurities can stabilize as magnetic insulators or spin gapless semiconductors.

Strong ferromagnetic coupling observed in zigzag-edged channels.

Abstract

We have investigated the electronic and magnetic response of a single Fe atom and a pair of interacting Fe atoms placed in patterned dehydrogenated channels in graphane within the framework of density functional theory. We have considered two channels: "armchair" and "zigzag" channels. Fully relaxed calculations have been carried out for three different channel widths. Our calculations reveal that the response to the magnetic impurities is very different for these two channels. We have also shown that one can stabilize magnetic impurities (Fe in the present case) along the channels of bare carbon atoms, giving rise to a magnetic insulator or a spin gapless semiconductor. Our calculations with spin-orbit coupling shows a large in-plane magnetic anisotropy energy for the case of the armchair channel. The magnetic exchange coupling between two Fe atoms placed in the semiconducting channel with an armchair edge is very weakly ferromagnetic whereas a fairly strong ferromagnetic coupling is observed for reasonable separations between Fe atoms in the zigzag-edged metallic channel with the coupling mediated by the bare carbon atoms. The possibility of realizing an ultrathin device with interesting magnetic properties is discussed.