| AVS 57th International Symposium & Exhibition | |
| Magnetic Interfaces and Nanostructures | Thursday Sessions |
| Session MI+TF-ThM |
| Session: | Magnetic Nanostructures, Thin Films and Heterostructures |
| Presenter: | G. Prathiba, IIT Madras, India |
| Authors: | G. Prathiba, IIT Madras, India S. Venkatesh, Tata Institute of Fundamental Research (TIFR), India N. Harish Kumar, IIT Madras, India |
| Correspondent: | Click to Email |
Transparent magnetic semiconductors are potential materials for multifunctional magneto-opto-electronic devices. Wide band gap oxides are the best candidates for transparent semiconductors. Following the prediction of Dietl et al.,1 on possible ferromagnetic ordering in wide band gap semiconductors doped with magnetic elements, the focus was on oxide dilute magnetic semiconductors. SrSnO3 is a wide band gap material with a direct band gap of 4.27 eV. At room temperature it crystallizes in perovskite orthorhombic structure. The electrical resistivity of SrSnO3 on forming solid solution with SrFeO3 decreases. SrSn0.95Fe0.05O3 thin films were prepared by RF magnetron sputtering on oxidized silicon (100) substrates at room temperature. The films were annealed at 1073 K for two hours. The as deposited films were found to be amorphous whereas the annealed films were polycrystalline in nature. The surface morphology of the films studied using Atomic Force Microscopy (AFM) showed low roughness value (Root mean square value of surface roughness – 2.02 nm). The resistivity of the film was measured using two probe method in the temperature range 200 to 300 K. The variation of resistivity with temperature exhibits semiconducting behaviour. Using Arrhenius plot [ρ = ρoexp(E/kT)] the activation energy was found to be 0.39 eV. The magnetic measurements done using Superconducting Quantum Interference Device (SQUID) magnetometer showed ferromagnetic ordering below 20 K.
Reference:
1T. Dietl, H. Ohno, F. Matsukura, J. Cibert and D. Ferrand, Science, 287 (2000) 1018