Departamento de Física Aplicada, CINVESTAV-Mérida, Apartado Postal 73 Cordemex, Mérida, Yucatán 97310, México.
Facultad de Ingeniería, Universidad Autónoma de Yucatán, Mérida, Yucatán 97310, México.
Phys Rev Lett. 2018 Aug 17;121(7):074302. doi: 10.1103/PhysRevLett.121.074302.
By combining vibrational annealing and shear dimensionality, we experimentally show (1) a fast reversible crystallization fcc-bct (face-centered cubic-body-centered tetragonal) in a granular system that is composed of dissipative millimeter-sized dry spheres, (2) a two-dimensional (planar) shear promotes self-assembly into an fcc crystal, while one-dimensional shear produces a bct crystal, and (3) in analogy with heterogeneous nucleation, a granular temperature gradient leads to the formation of crystal domains showing competition of polymorphic phases in the cold regions. Our findings suggest that controlling the directionality of the interactions steers to reversible crystallization of hard spheres, adds clues for theoretical studies, and provides a novel mechanism for the technological development of the applications of self-assembling phononic crystals.
通过结合振动退火和剪切维度，我们实验展示了（1）在由耗散的毫米级干球组成的颗粒系统中，快速可逆的 fcc-bct（面心立方-体心四方）结晶，（2）二维（平面）剪切促进自组装成 fcc 晶体，而一维剪切产生 bct 晶体，（3）与异质成核类似，颗粒温度梯度导致形成晶体域，在冷区表现出多晶相的竞争。我们的发现表明，控制相互作用的方向性可以引导硬球的可逆结晶，为理论研究提供线索，并为自组装声子晶体的应用技术发展提供了一种新的机制。
