1. Department of Chemistry; University Wuerzburg; LCTM, Roentgenring 11 97070 Wuerzburg Germany
2. TU Dresden; Institute of Materials Science; Helmholtzstr. 7 01069 Dresden Germany
3. Department of Physics, Faculty of Science; Minia University; 61519 Minia Egypt
4. Physics Department, Faculty of Science; Aswan University; 81528 Aswan Egypt
5. Fraunhofer IFAM; Winterbergstrasse 28 01277 Dresden Germany
6. Faculty of Natural Science II; Martin-Luther-University Halle-Wittenberg; von-Danckelmann-Platz 3 06120 Halle Germany