Prediction of ferromagnetism in GaN:Ag and SiC:Ag nanotubes

Ferromagnetism in single-walled (6,0) GaN(SiC):Ag nanotubes were studied based on ab initio simulations within a pseudopotential method. For the GaN:Ag single-walled nanosystems, the width of the band gap reduces with the increase of dopant concentration. While Ag-doped SiC nanotubes, the band gap of majority-spin states decrease and these systems show metallic character. The first-principles results of total energies for SiC(GaN):Ag nanotubes predicted the stability of the ferromagnetic and antiferromagnetic phase, respectively. The obtained values of total magnetic moments of Ag-GaN and Ag-SiC systems are ∼2.0 and ∼3.2 μ_B, respectively. The analysis of the results of density of states show the significant contribution to the magnetization of both defected GaN:Ag and SiC:Ag systems come from three nitrogen and carbon atoms which are bonded with the dopant. First-principles investigation, suggest that the SiC(GaN):Ag nanotubes can be made into magnetic materials, and these are promising candidates for electronic, optoelectronic, and spintronic devices.