Structural and magnetic studies on (Fe, Cu) co-doped ZnO nanocrystals

(Fe,Cu) co-doped ZnO nanocrystals have been prepared through wet chemical route using acetate based precursors over a wide concentration range. The samples have been characterized by X-ray fluorescence (XRF) measurements to find out the concentration of dopants while phase purity of the samples has been investigated by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) measurements. To have further micro structural insight, the samples have subsequently been subjected to synchrotron radiation based X-ray absorption spectroscopy (XAS) measurements comprising of both X-ray near edge structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) techniques. The results of the above measurements have been used to explain the magnetic properties of the samples which have further been corroborated by density functional theory (DFT) based electronic structure calculations. It has been observed that inclusion of Cu dopants in the samples in addition to Fe increases anti-ferromagnetic (AFM) correlation among the transition metal ions and thus decreases the ferromagnetic susceptibility of the samples.