[1] IPN, Ctr Invest & Estudios Avanzados, Dept Fis, Mexico City 07360, DF, Mexico
[2] Univ Nacl Autonoma Mexico, Fac Quim, Mexico City 04510, DF, Mexico
[3] Univ Nacl Autonoma Mexico, Inst Ciencias Fis, Cuernavaca 62251, Morelos, Mexico
[4] Inst Politecn Nacl ESIQIE, Mexico City 07738, DF, Mexico
[5] UPALM, Inst Politecn Nacl ESIT, Mexico City 07738, DF, Mexico