1. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei, P. R. China
2. Physics Department, Faculty of Science, Fayoum University, El Gomhoria Street, 63514 Fayoum, Egypt
3. Nanostructure Research Centre (NRC), Wuhan University of Technology, 122 Luoshi Road, 430070 Wuhan, Hubei P. R. China
4. Laboratory of Inorganic Materials Chemistry (CMI), University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium