EPR and TGA study of two Zn3Fe4V6O24−x samples prepared by different thermal treatments

Two samples of multicomponent vanadate, Zn3Fe4V6O24−x, compound have been prepared following two different thermal annealing processes. XRD measurements have shown the same values of lattice parameters for both samples. The TGA results indicate the possibility of oxygen deficiency. The EPR g-factor is the same for both samples, but large differences in the EPR amplitude and line width have been recorded. The integrated intensities of EPR lines differ slightly, what indicates a difference in the number of paramagnetic centers in the samples. The oxygen deficiency processes can introduce disorder and thus influence magnetic interactions in a multicomponent vanadate system. As a result, a slight change of technological conditions during sample preparation can cause drastic changes in physical properties and thus influence the application possibilities of this group of compounds.