Ferromagnetic properties in Fe-doped ZnS thin films

Fe-doped ZnS single-phase thin films showing ferromagnetism have been successfully prepared by metal-organic chemical vapor deposition (MOCVD) on GaAs substrates. Field and temperature dependent magnetization curve indicate that the sample with a Curie temperature T-c as high as 270K. The X-ray diffraction and atomic force microscopy (AFM) reveal that the thin films are well crystallized, Fe ions are substituted for Zn ions in the ZnS matrix and no trace of secondary phases or Fe clusters is detected. The experimental results are explained theoretically by spin-polarized density functional calculations within generalized-gradient approximations (GGA), which indicates the observed high T-c could be mainly ascribed to the p-d exchange coupling between Fe ions and host elements.