Mössbauer characterization of Fe-doped ZnO prepared by mechanical milling.

BAUM, LORENA; MEYER, MARCOS; RICHARD, DIEGO; DAMONTE, LAURA; MENDOZA ZÉLIS, LUIS

Foz do Iguassu, Brasil

Conferencia; XIV International Conference on Hyperfine Interactions; 2007

It is known that the wide band semiconductor ZnO doped with small quantities of magnetic atoms (Mn, Co, Fe and Ni) shows room temperature ferromagnetism. However, the mechanism responsible of such singular ferromagnetic behaviour is not yet well understood and moreover,   experimental evidences of the magnetic character are not conclusive. Many methods were used to prepare thin films materials like pulsed laser deposition, electrodeposition and other different chemical routes. In a previous work (1) we have prepared and magnetically characterized Zn1-xCoxO powders obtained by mechanical milling. In this work we continue with the preparation of massive ternary oxides Zn1-xFexO using the mechanical mill. The starting materials were Fe2O3, a-Fe or FeO. Parameters such as initial concentrations, atmosphere and milling times were varied. The structure evolution with milling time was analyzed by X-ray diffraction. Moessbauer spectroscopy was also applied to identify the intermediate and final products. Different phases were obtained according to the initial conditions (precursor used, atmosphere, etc.) and the enthalpies of phase’s formation.