Enhanced Ferromagnetic Stability in Cu Doped Passivated GaN Nanowires

TL;DR

This study uses density functional calculations to show that Cu-doped GaN nanowires exhibit enhanced room temperature ferromagnetism, which can be tuned by size, shape, and surface passivation, aligning with experimental results.

Contribution

It reveals that Cu dopants prefer proximity in GaN nanowires and highlights the importance of surface passivation for ferromagnetism, advancing understanding of magnetic properties in nanostructures.

Findings

Cu dopants are most stable when near each other.

Ferromagnetism is enhanced due to reduced Cu td band width in NWs.

Surface passivation is crucial for sustaining ferromagnetism.

Abstract

Density functional calculations are performed to investigate the room temperature ferromagnetism in GaN:Cu nanowires (NWs). Our results indicate that two Cu dopants are most stable when they are near each other. Compared to bulk GaN:Cu, we find that magnetization and ferromagnetism in Cu doped NWs is strongly enhanced because the band width of the Cu td band is reduced due to the 1D nature of the NW. The surface passivation is shown to be crucial to sustain the ferromagnetism in GaN:Cu NWs. These findings are in good agreement with experimental observations and indicate that ferromagnetism in this type of systems can be tuned by controlling the size or shape of the host materials.