Structure-dependent high-TC ferromagnetism in Mn-doped GeSe

Layered IV-VI diluted magnetic semiconductors (DMSs) have exhibited fascinating ferromagnetism down to atomic Layers, but their relatively Low Curie temperature (T-C <= 200 K) significantly hinders their practical application. In this work, Mn-doped GeSe (GeMnSe) DMSs with high-T-C ferromagnetism (FM) are synthesized by chemical vapor deposition. As the Mn concentration varies, the obtained sampLes exhibit various structures including single-crystalline nanocombs (SC-NCs), polycrystalline nanoparticLes (PC-NPs) and amorphous nanoaggregates (a-NAs). ALL the sampLes exhibit FM, and their T-C and saturation magnetization (Ms) are correlated to their structures. Notably, GeMnSe SC-NCs show a record high T-C of 309 K and a record strong magnetic moment of 4.37(mu B)/Mn compared to all the previously-reported IV-VI DMSs. Further analysis shows that the FM originates from the synergetic effect of the Ruderman-Kittel-Kasuya- Yoshida (RKKY) interaction, the crystalline order and the shape anisotropy in the samples. Our results provide a panorama of nanostructure-dependent FM in GeSe-based DMSs and suggest a peculiar Wayground for investigating fundamental physics and spintronic applications in IV-VI compounds.

Automated summary

Mn-doped GeSe diluted magnetic semiconductors with different nanostructures were synthesized and their ferromagnetic properties were investigated. The GeMnSe single-crystalline nanocombs showed the highest Curie temperature and magnetic moment. The ferromagnetism in these samples originates from the synergistic effect of interactions, crystalline order, and shape anisotropy. These findings provide a comprehensive understanding of nanostructure-dependent ferromagnetism in GeSe-based diluted magnetic semiconductors and offer new insights for studying fundamental physics and spintronic applications in IV-VI compounds.