[1] King Fahd Univ Petr & Minerals, Ctr Excellence Nanotechnol, Dhahran 31261, Saudi Arabia
[2] King Fahd Univ Petr & Minerals, Syst Engn, Dhahran 31261, Saudi Arabia
[3] Univ Putra Malaysia, Fac Sci, Dept Phys, Serdang 43400, Malaysia
[4] King Fahd Univ Petr & Minerals, Phys Dept, Dhahran 31261, Saudi Arabia