LAUSR

Abstract A detailed experimental and theoretical investigations on the origin of room temperature ferromagnetism in Fe doped CdS diluted magnetic semiconductor is reported in the present study. X-ray diffraction results reveal the cubic zinc blende CdS structure with an average crystallite size of 2 nm–3 nm which is in concurrence with the Transmission electron microscopy results. UV–visible spectroscopy depict the enhancement of optical band gap of Fe doped CdS nanoparticles compared to the bulk CdS as a result of the quantum confinement effect. Photoluminescence spectra revealed the presence of Cd2+ and S2− defect states in the nanoparticles in addition to the fluorescence quenching effect. FTIR results demonstrate the stretching vibrations of Cd S bond. Magnetic study confirms the existence of room temperature ferromagnetic ordering in the nanoparticles for the lower concentration of Fe, as a result of spin polarization induced by the Fe atoms to the nearest neighboring S atoms. At higher concentration of Fe, the enhanced antiferromagnetic interaction between short range Fe ions suppresses the ferromagnetic ordering. Theoretical calculations demonstrate the half metallic nature of Fe doped CdS system with strong p-d hybridization between the Fe-d states and the S-p states which results the room temperature ferromagnetism.