Fianti Fianti, Department of Physics, Semarang State University, Central Java,
Indonesia
Badrul Munir, Department of Metallurgical Engineering, University of Indonesia, Jakarta,
Indonesia
Kyoo Ho Kim, Department of Materials Science and Engineering, Yeungnam University, 214-1 Daedong, Gyeongsan, Gyeongbuk 712-749,
Korea, Republic of
Mohammad Ikhlasul Amal, Indonesian Institut of Sciences (LIPI), South Tangerang,
Indonesia
