1. Department of Physics National Dong Hwa University Hualien 97401 Taiwan
2. Department of Chemistry National Dong Hwa University Hualien 97401 Taiwan
3. Office of Postgraduate Studies, UCSI University Kuala Lumpur 56000 Malaysia
4. Functional Materials Research Laboratory School of Physical Sciences Punyashlok Ahilyadevi Holkar Solapur University Solapur 413255, M. S. India
5. Department of Physics Ahmednagar College Ahmednagar 414001, M. S. India