1. IPICyT, Instituto Potosino de Investigación Científica y Tecnologíca, Apartado Postal 3-74, Tamgamanga, San Luis Potosí, 78216, S.L.P., México
2. Department of Physical Engineering, Sciences and Engineering Division, University of Guanajauto Campus León, Lomas del Bosque 103, Fracc. Lomas del Campestre, León 37150, Guanajuato, México