【摘要】 使用第一性原理方法计算研究了一系列无限长、超细的钛金属线的结合能和电子性质,并得到了这些超细金属线的电导.结果表明,超细钛金属线单位原子的结合能比体材料的结合能低得多,而且与金属线截面半径的倒数在所计算的纳米范围内成线性反比关系.钛金属线的电子结构性质表现出渐进的尺寸演化和明显的结构关联,当金属线直径大于1 nm时表现出类似体材料的电子结构,这与Ti团簇的电子结构性质相似.对电导的计算发现,金属线的电导随着线尺寸的变粗而增大,电导通道的数目由金属线的结构对称性和粗细所决定.更多还原

【Abstract】 We carried out first-principle electronic structures and energy calculations for a series of infinitely long,ultrathin titanium wires.The electric conductance of these wires was computed.The present results show that,for the nanoscale regime we studied,the cohesive energies per atom of the wires are much lower than that of Ti bulk,and are roughly linear with the reciprocal of the radius of the wires.The electronic structures of the ultrathin wires show strong correlations to the sizes and structures of the wires and start to show bulk behavior when the wires are around 1 nm in diameter,which are similar to the properties of Ti clusters.The electric conductance of the wire increased as the diameter of the wire increased,and the number of channels open for conduction is decided by the size and structural symmetry of the wire.更多还原