A study of the size-dependent elastic properties of CdSe nanowires

The size dependence of elastic properties of CdSe nanowire in [0 0 0 1] direction is investigated by all atoms molecular dynamic simulation. We found that both the Young's modulus and Poisson ratio of the nanowires decrease with increasing radius, and the Young's moduli of the nanowires studied here are significantly higher than that of bulk material. The physical origin of the size dependence can be explained by the factor that high surface stiffness effect decays with decreasing surface to volume ratio. The results of VDOS show that the high frequency part will enhance as the nanowire radius decreases, this trend is consistent with that of the Young's modulus of the nanowires.