1. Engineering Physics Department, Faculty of Industrial Technology, Institut Teknologi Bandung, Bandung, West Java, Indonesia
2. Physics Department, Universitas PGRI Sumatera Barat, Padang, Sumatera, Indonesia
3. Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Bandung, West Java, Indonesia
4. Fakulti Kejuruteraan Mekanikal, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, Durian Tunggal, Melaka, Malaysia