非简谐振动对纳米金刚石表面性质的影响

摘要

借助米-里纳德-金斯势研究了纳米金刚石的Debye温度、表面能、表面压强、晶格参量随原子数和形状的变化规律，探讨了非简谐振动和形状对其表面性质的影响．结果表明：1）纳米金刚石的Debye温度和表面能随原子数的增多而增大，其中杆状的Debye温度和表面能要小于立方形的值；2）纳米金刚石的表面压强和低温时的晶格参量相对变化量随原子数Ⅳ的增多而减小，其中杆状的值要比立方形的值要大；3）原子数较少时，非简谐振动效应和形状对纳米晶的Debye温度、表面能、表面压强、晶格参量的影响显著．%The influences of atomic number and shape on Debye temperature, surface energy, surface pressure and lattice are studied by means of Me-lennard jones potential, then the influences of anharmonicity and shape on surface character are discussed. The result shows that （1） the Debye temperature and surface energy increase as atomic number increases, and that of rod nanodiamond is lower than that of cubic one. （2） The surface pressure and the variation of lattice parameter at low temperature decrease with the atom number decreasing, and the rod sample change is more apparent. The harmonic atomic surface pressure is smaller than the anharmonic one. （3） The above case is obvious when less atom number is small.