Letz M, Schilling R, Latz A
Johannes-Gutenberg-Universitat Mainz, D-55099 Mainz, Germany.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Oct;62(4 Pt B):5173-8. doi: 10.1103/physreve.62.5173.
For hard ellipsoids of revolution we calculate the phase diagram for the idealized glass transition. Our equations cover the glass physics in the full phase space, for all packing fractions and all aspect ratios X0. With increasing aspect ratio we find the idealized glass transition to become primarily driven by orientational degrees of freedom. For needlelike or platelike systems the transition is strongly influenced by a precursor of a nematic instability. We obtain three types of glass transition line. The first one (straight phi((B))(c)) corresponds to the conventional glass transition for spherical particles which is driven by the cage effect. At the second one (straight phi((B'))(c)), which occurs for rather nonspherical particles, a glass phase is formed that consists of domains. Within each domain there is a nematic order where the center of mass motion is quasiergodic, whereas the interdomain orientations build an orientational glass. The third glass transition line (straight phi((A))(c)) occurs for nearly spherical ellipsoids where the orientational degrees of freedom with odd parity, e.g., 180 degrees flips, freeze independently from the positions.
对于硬旋转椭球体，我们计算了理想化玻璃化转变的相图。我们的方程涵盖了全相空间中的玻璃物理，适用于所有填充率和所有纵横比(X_0)。随着纵横比的增加，我们发现理想化的玻璃化转变主要由取向自由度驱动。对于针状或板状系统，转变受到向列相不稳定性前驱体的强烈影响。我们得到了三种类型的玻璃化转变线。第一条（(\phi_{(B)c})直线）对应于球形颗粒的传统玻璃化转变，它由笼效应驱动。第二条（(\phi_{(B')c})直线）出现在相当非球形的颗粒中，形成的玻璃相由畴组成。在每个畴内存在向列序，其中质心运动是准遍历的，而畴间取向形成取向玻璃。第三条玻璃化转变线（(\phi_{(A)c})直线）出现在近球形椭球体中，其中具有奇宇称的取向自由度，例如(180)度翻转，与位置无关地冻结。
