Structural and Size Effects of Mechanical, Thermodynamic,and Electronic Properties in Titanium Nanowires
WANG Bao-lin 1,2 , WANG Guang hou 2 (1. Department of Physics, Huaiyin Teachers College, huaian 223001, China) (2. National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University, Nanjing 210093, China)
Some typical structures of titanium nanowires, i.e. four strands helical, centered pentagonal, hexagonal and the thicker hexagonal structures are chosen to study the structural and size effects of ultrathin nanowires. The angular correlation functions and vibrational properties are discussed. We have further calculated the electronic structures of the titanium nanowire by using density functional electronic structure self consistent field (SCF) calculations with the plane wave pseudopotential method. The vibrational and electronic properties of titanium nanowire depend on the structure and size. Bulk like continuous electronic band are formed in the Ti wires thicker than 1 nm. We have studied the thermal stability of the titanium nanowires by using molecular dynamical simulation (MD) starting from the optimized structures. The structural transformation from the helical multi shell cylindrical to the bulk like for the thicker nanowire is observed which takes place in the melting process. The thermal properties of titanium nanowires are significantly dependent on the structure and size of the nanowires.