Neutron diffraction study and ab-initio calculations of nanostructured doped ZnO

• Published in: Journal of alloys and compounds 2012-09, Vol.536, p.66-72
• Main Authors: Bououdina, M., Mamouni, N., Lemine, O.M., Al-Saie, A., Jaafar, A., Ouladdiaf, B., El Kenz, A., Benyoussef, A., Hlil, E.K.
• Format: Article
• Language: English
• Subjects: Ab-initio calculations; Condensed Matter; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Doping; Exact sciences and technology; Magnetic properties; Materials Science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Nanostructured ZnO; Neutron diffraction; Neutron diffraction and scattering; Physics; Single-crystal and powder diffraction; Structure of solids and liquids; crystallography
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.04.055

Magnetization, neutron diffraction and KKR-CPA calculations are employed to investigate the magnetic properties of nanostructured doped ZnO. Nanostructured doped-ZnO system with various elements (M=Cr, Mn, Fe, Co, Ni, and In) at 10at.% doping concentration, was investigated. Neutron diffraction refinements confirm the stability of the würztite crystal structure of the parent compound ZnO, the localization of the doping elements within Zn sites, and some residual impurities. Magnetic measurements show a ferromagnetic behavior at room temperature where the magnetic parameters, saturation magnetization (Ms), remanence (Mr) and coercivity (Hc) vary considerable according to the nature of the doping elements, its valence and its solubility level: Ms has the highest value of 0.223emu/g for Ni and lowest value of 0.011emu/g for Cu. The ab-initio calculations using DFT method confirm the ferromagnetism of doped-ZnO in agreement with magnetic measurements. It is found that oxygen plays an important role to explain the magnetic properties observed in diluted magnetic semiconductors (DMS) of the studied doped-ZnO system. The estimated Curie temperature was found to vary considerably according to the nature of the doping element, with the lowest value for In (105K) and highest value for Co (737K).