[1] Le Quy Don Tech Univ, Dept Mat Sci & Engn, Hanoi, Vietnam
[2] Hue Univ, Univ Educ, Dept Phys, Hue, Vietnam
[3] Duy Tan Univ, Inst Res & Dev, Da Nang 550000, Vietnam
[4] Duy Tan Univ, Fac Nat Sci, Da Nang 550000, Vietnam
[5] Dong Thap Univ, Div Theoret Phys, Dong Thap, Vietnam
[6] Ton Duc Thang Univ, Adv Inst Mat Sci, Lab Appl Phys, Ho Chi Minh City, Vietnam
[7] Ton Duc Thang Univ, Fac Appl Sci, Ho Chi Minh City, Vietnam