单晶ZnO、TiO_2纳米线拉伸力学特性的分子动力学研究  

MD simulations on tension of single-crystal ZnO and TiO_2 nanowires

作　　者：王继亮[1] 沈海军[1] 

机构地区：[1]南京航空航天大学航空宇航学院,南京210016

出　　处：《原子与分子物理学报》2010年第6期1157-1161,共5页Journal of Atomic and Molecular Physics

摘　　要：采用分子动力学方法,模拟了不同加载速度、不同温度下单晶ZnO、TiO_2纳米线的拉伸破坏过程.通过模拟结果,对比、分析了两种单晶金属氧化物纳米线拉伸力学特性的差异.研究表明,1)ZnO纳米线的断裂机制为:表面微裂纹-微孔-微裂纹与微孔贯穿-断裂,而TiO_2纳米线的断裂机制为:局部屈服-颈缩-断裂;2)TiO_2纳米线的承载能力优于ZnO纳米线,而承受变形的能力劣于ZnO纳米线;3)温度较低的情况下,纳米线的抗拉性能较好;加载速度越高,纳米线的抗载性能越好,而抗变形能力越差.By the MD（Molecular dynamics） method, the tensile fracture of the single-crystal ZnO and TiO2nanowires at different temperature and different loading-velocity was simulated. According to the simulated results, the differences of the tensile-properties of the two nanowires were compared and discussed. It is shown that （1） the ZnO nanowire has the following fracture-mechanism： ＂surface micro- cracks, micro-holes, transfixion between the micro-cracks and micro-holes, and fracture＂; the TiO2 nanowire has the mechanism of ＂local yielding, neck-shrinking and fracture＂, （2） the TiO2 nanowire has the better loading-support capability but the worse deformation-support capability than ZnO nanowire, and （3） the two nanowires have better anti-tension capability at lower temperature; the higher the loading-velocity, the better their loading-support capability, and the worse their deformation-support capability.

关 键 词：ZnO、TiO2 纳米线 分子动力学 拉伸特性 

分 类 号：TQ050.4[化学工程]