Impurity Atoms in Electrodeposited Films And Milled Powders of ZnMO (M=Co, Mn)

J. HOYA; J.I. LABORDE; M. MEYER; L.C. DAMONTE; L. A. MENDOZA ZÉLIS

Campinas

Congreso; Reunion Anual de Usuarios de Laboratorios de Luz Sincrotron; 2013

Laboratorio Nacional de Luz Sincrotron UNICAMP

(Zn, Mn)O and (Zn, Co)O appears as new promising materials for spintronic. Some authors observed ferromagnetic behavior even at room temperature in these so called diluted magnetic semiconductors (DMS) materials, but the origin of this behavior is still controversial. Although some researchers have claimed that the origin of ferromagnetism is related to the formation of Co-rich clusters, the source of the observed ferromagnetism is far from being clear. In previous works, we have analyzed the magnetic properties of mechanically milled powders [1] and electrodeposited films [2] of ZnFeO or ZnCoO samples. In these cases, ZnCoO samples are paramagnetic, what in principle is an indication of a homogeneous distribution of Co into the ZnO matrix. However ZnMnO reveals an antiferromagnetic behavior for high contents of Mn.  Therefore taking advantage of synchrotron radiation capabilities for the residual elemental detection inside Mn-rich or Co-rich clusters, we attempt an EXAFS characterization of these Zn1−xMxO (M: Mn, Fe and Co) samples. The results are discussed taking into account previous studies made by X-ray diffraction, Mössbauer Spectroscopy and magnetic measurements in a Quantum Design MPMS-5S superconducting quantum interference device (SQUID) magnetometer.