Producing ZnFe2O4 thin films from ZnO/FeO multilayers

Abstract

The present work investigates the structural and magnetic properties of ZnFe2O4 thin films obtained from ZnO/FeO multilayers deposited on MgO substrate by DC reactive sputtering. We show that this method is good to grow efficiently ordered ZnFe2O4 films. The quality of the thin films is ensured by TEM measurements, which showed a well ordered film of ZnFe2O4. The magnetic properties of these thin films present still minimal differences when compared to bulk ZnFe2O4 powders. They exhibit a ferromagneticlike behavior at low temperatures, whereas ZnFe2O4 is expected to be antiferromagnetic. We found that the magnetic signal originated from the film surface, where cation inversion was visible from grazing incidence X-ray fluorescence measurements. The inversion of Fe ions with Zn ions caused a magnetic spin glass state, which created then the ferromagnetic-like behavior differently to bulk ZnFe2O4. These <br />facts point to possible routes in order to improve the growing process of ZnFe2O4 via ZnO/FeO multilayers.