纳米一维双原子晶体颗粒的原子均方位移和均方速度

Mean-square displacements and mean-square velocities of atoms in one dimensional diatomic nanoparticles

应用作者与合作者已导出的纳米一维双原子晶体颗粒的位移 位移格林函数 ,推导了纳米一维双原子晶体颗粒的速度 速度格林函数 ,并在此基础上 ,应用涨落 耗散定理 ,推导了纳米一维双原子晶体颗粒的原子均方位移公式和原子均方速度公式。数值计算表明 ,纳米晶体颗粒表面原子的均方位移大于内部的原子均方位移 ,而表面原子的均方速度小于内部原子的均方速度 ;当纳米颗粒尺寸减小时 ,表面原子的均方位移和内部原子的均方位移都减小 ,而表面原子的均方速度和内部原子的均方速度几乎不发生变化 ;温度增大时 ,纳米晶体颗粒中各原子的均方位移和均方速度都增大 ,在高温极限 ,各原子的均方位移和均方速度与温度成正比。

Based on the displacement displacement Greens function of one dimensional diatomic nanoparticle that was deduced earlier by the author and his collaborator, the velocity velocity Greens function is deduced, and then the formulas of mean square displacements and mean square velocities of atoms are deduced with the aid of the Fluctuation dissipation theorem. The numerical results show that the mean square displacements of the surface atoms are larger than those of the inner atoms, but the mean square velocities of the surface atoms are smaller than those of the inner atoms. The mean square displacements of the surface atoms and inner atoms increase when the size of particles increase, but the mean square displacements and the mean square velocities of all atoms increase when the temperature increase, at the high temperature limit, they are directly proportional to temperature.