1. Electronic Properties of Materials, Faculty of Physics, University of Vienna; Strudlhofgasse 4 1090 Vienna Austria
2. College of Nanotechnology, King Mongkut's Institute of Technology Ladkrabang; Chalongkrung Road, Ladkrabang 10520 Bangkok Thailand
3. National Metal and Materials Technology Center; Phahonyothin Road, Khlong Luang 12120 Pathumthani Thailand
4. Faculty of Science, Department of Physics, Burapha University; Long-Hard Bangsaen Road, Muang 20131 Chonburi Thailand