Probing the electronic structure and magnetism in Ni doped ZnTe: A DFT modeling and experiment

Abstract

This work deals with investigation of Zn1-xNixTe (x = 0.0, 0.06, 0.12) to understand physical properties determined using experimental and theoretical routes. The XRD results reveal polycrystalline cubic structure with preferential orientation along (111). The FE-SEM analysis showed that grain size of pure ZnTe is 51 nm that increases to 93 nm due to Ni incorporation. DFT was also employed to analyze the calculated electronic structures with experimental data and ferromagnetism. The electron density analysis shows the polar covalent nature of the studied alloys. The ferromagnetic nature and its thermodynamic stability is confirmed due to more energy released in FM phase than in the antiferromagnetic (AFM) phase and negative sign of formation energy. The room temperature (RT) ferromagnetism is established by Heisenberg classical model. The shifting of magnetic moment (μB) from Ni site to nonmagnetic sites is observed. The direct exchange, indirect exchange and crystal field energies as well as the exchange constants (Noα = Noβ) confirmed that the cause of ferromagnetism is exchange mechanism instead clustering of Ni which increases the importance of studied alloys for spintronic applications.