Molecular dynamics for Ti-Ni dimer adsorbed on pristine and defective graphene

Motivated by the oxidation and corrosion processes of the nitinol alloy that has been used in biological applications, we show initial first principles calculations for the interaction of the Ti-Ni dimer, the simplest nitinol alloy, with a graphene layer, (gl). We have selected the graphene layer for the interaction, because our results can be compared with similar results for the interaction of many substances with a graphitic system as the gl. The results of several relaxations of the system Ti-Ni-gl shows that the dimer has been adsorbed to the gl. Temperatures of 300, 800, 1100 and 1300 K are not enough to desorb the dimer from the gl, these results are obtained from the molecular dynamics for those temperatures. The metallic character of the system is obtained from the density of states and projected density of states. Similar results are obtained for the interaction of the dimer when there are one or two carbon vacancies on the gl. (paper)