1Universidade Federal de Ouro Preto–UFOP, Ouro Preto, MG 35400–000, Brazil
2School of Chemical and Physical Sciences, Keele University, Keele, ST5 5BG, United Kingdom
3Department of Physics, Quaid-i-Azam University, Islamabad 45320, Pakistan
4Universidade Federal de Alfenas – UNIFAL, Alfenas 37130–000, Brazil