State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, China.
Phys Rev Lett. 2011 Jul 1;107(1):015501. doi: 10.1103/PhysRevLett.107.015501. Epub 2011 Jun 29.
First-principles molecular dynamics simulation reveals the effects of electronic excitation in the amorphization of Ge-Sb-Te. The excitation makes the phase change an element-selective process, lowers the critical amorphization temperature considerably, for example, to below 700 K at a 9% excitation, and reduces the atomic diffusion coefficient with respect to that of melt by at least 1 order of magnitude. Noticeably, the resulting structure has fewer wrong bonds and significantly increased phase-change reversibility. Our results point to a new direction in manipulating ultrafast phase-change processes with improved controllability.
第一性原理分子动力学模拟揭示了电子激发在 Ge-Sb-Te 非晶化过程中的作用。激发使相变成为一种元素选择性过程，大大降低了临界非晶化温度，例如在 9%的激发下，温度可降至 700 K 以下，并使原子扩散系数相对于熔体降低至少 1 个数量级。值得注意的是，所得结构具有更少的错误键，并且显著提高了相变的可逆性。我们的结果为通过提高可控性来操纵超快相变过程指出了一个新的方向。
