Propriedades eletrônicas, ópticas e vibracionais de nanoestruturas TMDs RuX2(X= S, Se e Te) via DFT.

Abstract

With the discovery of graphene in 2004, a new line of research in two-dimensional materials was developed. As this innovation we find the transition metal dichalcogenides (TMD) materials that became known as last generation graphene since these systems have many degrees of freedom to be explored and understood. In this work, we performed textitabinitio calculations, based on the density functional theory implemented in the CASTEP code, for theoretical understanding of RuX2 crystalline systems, investigating the structural, electronic, vibrational, thermal and optics. As a result, it was seen that all RuX2 with ( X= S, Se and Te) systems have indirect gap semiconductor characteristics for both GGA and LDA approaches. In addition, as mechanical stability is a very important point in the theoretical study, through the spectrum and density of phonon states, we verified only positive frequencies, confirming the stability of the structures. Due to the thermodynamic functions (enthalpy, entropy, free energy and thermal capacity), we have indications of how the structure formation process occurs (free from impurity and with impurity). Another important factor is the rigidity of our systems. For information about it, Debye’s temperature was calculated.