DFT study of the density of states and ferromagnetic properties of Ag-doped zinc oxide nanocomposites

The electronic and magnetic properties of single-walled silver-doped ZnO nanotubes with (6,0) chirality were investigated using Density Functional Theory within the Local Spin Density Approximation, employing the Quantum ATK atomic-scale modeling simulation code.The incorporation of silver atoms into the ZnO nanotube structure was found to significantly modify the electronic band structure of these nanocomposites.For pristine single-walled ZnO nanotubes, the calculated band gap was about 3.10 eV, indicating semiconducting behavior.However, after doping with silver, the band gap decreased notably, suggesting enhanced electronic conductivity.Furthermore, the total magnetic moment of the ZnO:Ag nanocomposite was estimated to be approximately 1.0 B, primarily attributed to the contribution of impurity dstates, which play a crucial role in inducing magnetization within the system.First-principles calculations comparing total energies for ferromagnetic and antiferromagnetic configurations indicated that the ferromagnetic state is energetically more favorable for Ag-doped ZnO nanotubes, confirming their magnetic stability.These results demonstrate that silver doping induces a transition in ZnO nanotubes towards a ferromagnetic and semi-metallic character.Consequently, ZnO nanotubes doped with silver emerge as promising candidates for future spintronic devices, where spin-dependent electronic properties can be exploited for advanced technological applications.Our findings provide valuable insights into tuning the electronic and magnetic characteristics of ZnO-based nanostructures through controlled doping strategies