Long-Range Topological Order in Metallic Glass
Long-Range Topological Order in Metallic Glass
复制标题
金属玻璃中的长程拓扑序
DOI：
10.1126/science.1200324
复制
发表时间：
2011-06-17
期刊：
影响因子：
56.9
通讯作者：
Mao, Ho-Kwang
中科院分区：
文献类型：
--
作者：
Zeng, Qiaoshi;Sheng, Hongwei;Mao, Ho-Kwang
玻璃缺乏作为晶体特征的长程周期性秩序。然而，在Ce75Al25金属玻璃（MG）中，我们发现了对应于无限长单晶的长程拓扑有序。结构检查证实，MG是真正的无定形，各向同性，无应变，但在25吉帕斯卡的静水压力下，每一段厘米长的MG带独立析晶成面心立方（fcc）晶体具有相同的取向。通过使用分子动力学模拟和同步辐射X射线技术，我们阐明，大Ce和小Al原子之间的失配挫败的结晶，并导致非晶化，但长程面心立方拓扑秩序仍然存在。压力诱导Ce中的电子跃迁，消除了失配，并通过形成单晶来体现拓扑有序。
Glass lacks the long-range periodic order that characterizes a crystal. In the Ce75Al25 metallic glass (MG), however, we discovered a long-range topological order corresponding to a single crystal of indefinite length. Structural examinations confirm that the MG is truly amorphous, isotropic, and unstrained, yet under 25 gigapascals hydrostatic pressures, every segment of a centimeter-length MG ribbon devitrifies independently into a face-centered cubic (fcc) crystal with the identical orientation. By using molecular dynamics simulations and synchrotron x-ray techniques, we elucidate that the mismatch between the large Ce and small Al atoms frustrates the crystallization and causes amorphization, but a long-range fcc topological order still exists. Pressure induces electronic transition in Ce, which eliminates the mismatch and manifests the topological order by the formation of a single crystal.