1. School of Materials Science and Engineering; Changwon National University; Changwon Gyeongnam 641-773 South Korea
2. Department of Physics; Changwon National University; Changwon Gyeongnam 641-773 South Korea
3. Department of Advanced Materials Engineering; Keimyung University; Daegu 704-701 South Korea
4. Department of Physics Education; Pusan National University; Busan 609-735 South Korea