1. Department of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh
2. Department of Physics, Rajshahi University of Engineering and Technology, Rajshahi 6204, Bangladesh
3. School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia
4. Department of Physics, University of Rajshahi, Rajshahi 6205, Bangladesh
5. School of Chemistry and Physics and QUT Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia
6. School of Physics, University of New South Wales, Sydney, NSW 2052, Australia