Local crystalline order in a 2D colloidal glass former
Local crystalline order in a 2D colloidal glass former
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DOI：
10.1140/epje/i2007-10270-8
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发表时间：
2008-05-01
影响因子：
1.8
通讯作者：
Maret, G.
中科院分区：
文献类型：
--
作者：
Ebert, F.;Keim, P.;Maret, G.
两种具有长程偶极相互作用的超顺磁性胶体粒子的混合物被重力限制在悬挂水滴的平坦界面上。通过视频显微镜观察颗粒，并通过外部磁场控制偶极相互作用强度。通过对相关函数和键序统计得到的局部结构作为系统温度和相对浓度的函数进行了研究。虽然该系统没有长程有序，并表现出玻璃态动力学，不同类型的稳定微晶共存。全局无序结构的局部有序性由一小部分特定的晶体结构来解释。晶胞的统计数据表明，随着系统温度的降低，局部有序度不断增加，并且依赖于样品历史和局部组成。
A mixture of two types of super-paramagnetic colloidal particles with long-range dipolar interaction is confined by gravity to a flat interface of a hanging water droplet. The particles are observed by video microscopy and the dipolar interaction strength is controlled by an external magnetic field. The local structure as obtained by pair correlation functions and bond order statistics is investigated as a function of system temperature and relative concentration. Although the system has no long-range order and exhibits glassy dynamics, different types of stable crystallites coexist. The local order of the globally disordered structure is explained by a small set of specific crystal structures. The statistics of crystal unit cells show a continuous increase of local order with decreasing system temperature as well as a dependence on sample history and local composition.