Y.E. Gunanto
University of Pelita Harapan, Karawaci, Tangerang 15811, Indonesia
Indonesia

Dept. of Physics Edu.

W.A. Adi
Center for Science and Technology of Advanced Materials, National Nuclear Energy Agency, Puspiptek Area Serpong, Tangerang Selatan 15310, Indonesia
Indonesia

Center for Science and Technology of Advanced Materials, BATAN, Tangerang Selatan 15314, Indonesia

B. Kurniawan
University of Indonesia, Depok, 16424, Indonesia
Indonesia

Dept. of Physics, University of Indonesia, Depok, 16424, Indonesia

A. Purwanto
STKIP Surya, Tangerang 15811, Indonesia
Indonesia

Dept. of Physics,

T. Ono
Department of Physics, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
Japan

Department of Physics

H. Tanaka
Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
Japan

Dept. of Physics

E. Steven
National High Magnetic Field Lab., Tallahase, Florida, USA
Indonesia

Dept. of Physics