Self-diffusion dynamics processes relevant to 2D homoepitaxy growth of Ni adatom on Ni(111) surface

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• 作者：Fusheng Liu^a ; Yifeng Chen^a ; ^{yefengc63@sina.com" class="auth_mail} ; Yufei Wang^a ; ^{yejin802@126.com" class="auth_mail} ; Zhulin Liu^a ; Zhongliang Hu^a ; Xiyuan Yang^b ; Wenhua Luo^c
• 关键词：Adatom ; Crystal growth ; Diffusion dynamics ; Step
• 刊名：Physica B
• 出版年：1 July 2014
• 年：2014
• 卷：444
• 期：Complete
• 页码：1-5
• 全文大小：867 K

文摘

Using molecular dynamics and modified analytic embedded atom methods, the atomic self-diffusion dynamics behaviors relevant to 2D crystal growth on Ni(111) surface have been studied between 150 and 600 K. On perfect Ni(111) surface, the activation energy and prefactor are 0.058±0.001 eV and 4.2×10⁻⁴ cm²/s between 150 and 350 K, and 0.082±0.003 eV and 7.8×10⁻⁴ cm²/s from 400 to 600 K. Ni adatom just hops along the directions of close-packed steps on stepped Ni(111) surface, the corresponding activation energies and prefactors are 0.188±0.002 eV and (3.8–4.4)×10⁻³ cm²/s along the direction of A-type step, 0.140±0.001 eV and (1.1–1.2)×10⁻³ cm²/s along the direction of B-type step, and both fitting lines of Arrhenius law intersect at T_c=420–440 K. Our results show that the atomic growth dynamics under nonequilibrium conditions is gradually dominated by the prefactor with increasing temperature. In addition, the shape-change of the 2D nanometer-size island has been discussed on stepped Ni(111) surface in different temperature range.