Confirmation of room-temperature long range magnetic order in GaN:Mn

TL;DR

This study confirms room-temperature long-range magnetic order in GaN:Mn thin films using nano-scale characterization techniques, ruling out nano-clusters and suggesting delocalized electrons as a possible mechanism.

Contribution

It introduces a nano-scale characterization method to confirm long-range magnetic order in GaN:Mn, clarifying the origin of room-temperature ferromagnetism.

Findings

Long-range magnetic order confirmed in GaN:Mn

Nano-clusters are not responsible for ferromagnetism

Delocalized electrons may facilitate magnetic order

Abstract

We propose a method for nano-scale characterization of long range magnetic order in diluted magnetic systems to clarify the origins of the room temperature ferromagnetism. The GaN:Mn thin films are grown by metal-organic chemical vapor deposition with the concentration of Ga-substitutional Mn up to 3.8%. Atomic force microscope (AFM) and magnetic force microscope (MFM) characterizations are performed on etched artificial microstructures and natural dislocation pits. Numerical simulations and theoretical analysis on the AFM and MFM data have confirmed the formation of long range magnetic order and ruled out the possibility that nano-clusters contributed to the ferromagnetism. We suggest that delocalized electrons might play a role in the establishment of this long range magnetic order.