An Investigation of the Mechanism on Interfacial Charge Transformation of the TiB2/Cu Composites Studied by the First Principles

The charge communications have been widely existed in the metal materials when they are under the processing, the modeling and the failing. We studied the interfacial charge transformation of the TiB2/Cu composites via the first principles method. The layer thickness was predicted by the interfacial charge communications performed on the regions of the TiB2/Cu interfaces. The layer thickness of the Ti-terminated (TT)TiB2/Cu were predicted longer than those of the B-terminated(BT) TiB2/Cu and contrasting with their average vales as 0.75 (nm) and 0.65 (nm), respectively. The Mulliken population was applied to investigate the bond length, bond population and charge transformation of the six TiB2/Cu models. The Ti-Cu bond was only detected in TT-HCP interfaces among the all TT-TiB2/Cu models, which was further confirmed that the metallic bond of the Ti-Cu with the bond length and population as 2.5 Å and 0.22, respectively. Nevertheless, the B-Cu bond were detected in all BT-TiB2/Cu models, and the bond length and population higher than those of B-Cu bond in chemical complexes. The 5 atomic layers were involved in quantitative analyses of the interfacial charge transformation. The results indicate that the charges lost by interfacial Ti atom were inequivalent obtained by Cu and B atoms which nearby the interfacial Ti atoms of the TT-TiB2/Cu. Comparing with the BT-TiB2/Cu models, the charges acquired by the interfacial B atom were most from the Ti and less from the Cu atoms surrounded the interfacial B atoms.