1. Advanced Materials Research Unit; Department of Chemistry; Faculty of Science; King Mongkut's Institute of Technology Ladkrabang; Bangkok 10520 Thailand
2. Electroceramic Research Laboratory; College of Nanotechnology; King Mongkut's Institute of Technology Ladkrabang; Bangkok 10520 Thailand
3. Department of Chemical Engineering; Mahidol University; Nakorn Pathom 73210 Thailand