1. Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, Illinois 61801, USA
2. Department of Physics, Aberystwyth University, Penglais, Aberystwyth, Ceredigion SY23 3BZ, United Kingdom
3. Department of Physics, King Fahd University, Dhahran 34463, Saudi Arabia
4. Department of Metallurgical and Materials Engineering, Iskenderun Technical University, 31200 Hatay, Turkey