Temperature Driven Phase Transition at the Antimonene/Bi2Se3 van der Waals Heterostructure
Temperature Driven Phase Transition at the Antimonene/Bi2Se3 van der Waals Heterostructure
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DOI：
10.1021/acsnano.9b04377
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发表时间：
2019-09-01
期刊：
影响因子：
17.1
通讯作者：
Flammini, Roberto
中科院分区：
文献类型：
--
作者：
Hogan, Conor;Holtgrewe, Kris;Flammini, Roberto
我们发现了温度引起的锑的α和β结构之间的相变。当Sb在室温下沉积在硒化铋上时，它形成了相对于衬底具有不同取向的α-Sb的磁区。在温和的退火过程中，贝塔相长大并超过阿尔法相，最终形成一个与硒化铋表面晶格结构完美匹配的单一磁区。这种范德华异质结构的第一性原理热力学计算解释了两相随温度变化的不同稳定性，揭示了最小能量跃迁路径。虽然独立的α-和β-锑的形成能仅略有不同，但在退火态的异质结构中，由于完美晶格匹配导致与衬底的相互作用增强，最终有利于β相的形成。
We report the discovery of a temperature-induced phase transition between the alpha and beta structures of antimonene. When antimony is deposited at room temperature on bismuth selenide, it forms domains of alpha-antimonene having different orientations with respect to the substrate. During a mild annealing, the beta phase grows and prevails over the alpha phase, eventually forming a single domain that perfectly matches the surface lattice structure of bismuth selenide. First-principles thermodynamics calculations of this van der Waals heterostructure explain the different temperature-dependent stability of the two phases and reveal a minimum energy transition path. Although the formation energies of freestanding alpha-and beta-antimonene only slightly differ, the beta phase is ultimately favored in the annealed heterostructure due to an increased interaction with the substrate mediated by the perfect lattice match.