【摘要】 采用三维分子动力学模拟方法和Finnis-Sinclair型多体势,以[111]晶向银纳米杆为研究对象,模拟研究不同尺寸纳米杆在不同温度弛豫过程中的动态平衡变化过程,分析研究弛豫后银纳米杆的稳态结构变化、平均势能的变化及其在不同时刻结构的演变过程.结果表明,温度对银纳米杆结构稳定性将产生重大影响,银纳米杆存在一临界失稳温度,当温度小于临界失稳温度时,体系保持完好线状晶态,当温度大于临界失稳温度小于熔点时,体系坍塌熔化后发生重结晶,体系形成由(111)和(100)面围成的多面体;随银纳米杆截面尺寸增大,其临界失稳温度、熔点均增大,当截面尺寸大于2 nm时,临界失稳温度趋近于熔点,失稳现象只在一很窄温度区域内存在.更多还原

【Abstract】 A three-dimensional molecular dynamics method with Finnis-Sinclair embedded atom potentials is used to study relaxtion of fcc Ag nanorods with crystallographic orientation[111] .Homeostasis of Ag nanorod relaxation is shown.Stable structures and potential energies and structure evolution of Ag nanorod are studied. A critical temperature of destabilization(T_c) is found.As temperature of the nanorod is less than T_c,the system keeps intact line form of crystal.As temperature is higher than T_c and less than melting point,the system collapses,fuses and then recrystallizes.As temperature is near melting point,a stable polyhedron bounded by(111) and(100) facets forms. As cross-section of Ag nanorod increases T_c and melting point decrease.As cross-section dimension is larger than 2 nm,T_c is close to the melting point.Destabilization exists in a narrow temperature range.更多还原