Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
Phys Rev Lett. 2011 Aug 5;107(6):065702. doi: 10.1103/PhysRevLett.107.065702. Epub 2011 Aug 1.
We observed a two-step glass transition in monolayers of colloidal ellipsoids by video microscopy. The glass transition in the rotational degree of freedom was at a lower density than that in the translational degree of freedom. Between the two transitions, ellipsoids formed an orientational glass. Approaching the respective glass transitions, the rotational and translational fastest-moving particles in the supercooled liquid moved cooperatively and formed clusters with power-law size distributions. The mean cluster sizes diverge in power law as they approach the glass transitions. The clusters of translational and rotational fastest-moving ellipsoids formed mainly within pseudonematic domains and around the domain boundaries, respectively.
我们通过视频显微镜观察到胶体椭球单层中的两步玻璃化转变。在旋转自由度中的玻璃化转变发生在比平移自由度更低的密度下。在这两个转变之间，椭球形成了一个取向玻璃。在接近各自的玻璃化转变时，过冷液体中旋转和平移最快的粒子协同运动，并形成具有幂律尺寸分布的团簇。当接近玻璃化转变时，平均团簇尺寸呈幂律发散。平移和旋转最快的椭球团簇主要分别在赝向畴内和畴界周围形成。
