Vacancy induced ferromagnetism in SrWO_4 and SrMoO_4 nano structured compounds

摘要

The ferromagnetic ordering in the presence of oxygen vacancy has been investigated in SrWO_4 and SrMoO_4 compounds. Poly crystalline SrWO_4 and SrMoO_4 compounds were synthesized by simple chemical precipitation method. Powder X-ray diffraction (XRD) reveals the scheelite tetragonal structure for the compounds. The grain size and lattice strain of the compounds were estimated. The local order and disorder of the compounds was investigated by Raman spectroscopy. The formation micro spheres like shape of samples was examined SEM images. Evidence of oxygen vacancy and Oxidation states of the compounds were analyzed by X-ray photoelectron spectroscopy (XPS). In the UV-Vis spectra distinctive shift of the absorption edge energy was observed exclusively for SrWO_4. The enhanced ferromagnetic ordering in the prepared samples has been understood in terms of oxygen vacancy.