Justo JF, Cai W, Bulatov VV
Instituto de Fisica da Universidade de Sao Paulo, CP 66318, CEP 05315-970, Sao Paulo-SP, Brazil.
Phys Rev Lett. 2000 Mar 6;84(10):2172-5. doi: 10.1103/PhysRevLett.84.2172.
Competition between the two alternative positions (shuffle and glide 111 plane subsets) for the core of a 30 degrees partial dislocation in Si is examined. Using a combination of ab initio total energy calculations with finite temperature free-energy calculations based on an interatomic potential, we obtained free energies for the relevant vacancy-type core defects. Generally, the free energy of vacancy formation in the core of a 30 degrees glide partial dislocation is considerably lower (by more than 1 eV) than in the bulk. However, even at high temperatures, the predicted thermal concentration of the shuffle segments comprised of a row of vacancies in the core is low, placing the 30 degrees partial dislocation in the glide subset position.
研究了硅中30度部分位错核心处两个替代位置（洗牌和滑移111平面子集）之间的竞争。通过将从头算总能量计算与基于原子间势的有限温度自由能计算相结合，我们获得了相关空位型核心缺陷的自由能。一般来说，30度滑移部分位错核心处的空位形成自由能比体相中低得多（超过1电子伏特）。然而，即使在高温下，预测的由核心中一排空位组成的洗牌段的热浓度也很低，这使得30度部分位错处于滑移子集位置。
