Dislocation-mediated melting near isostructural critical points

被引:38
作者
Chou, T [1 ]
Nelson, DR [1 ]
机构
[1] HARVARD UNIV,DEPT PHYS,CAMBRIDGE,MA 02138
来源
PHYSICAL REVIEW E | 1996年 / 53卷 / 03期
关键词
D O I
10.1103/PhysRevE.53.2560
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
We study the interplay between an isostructural critical point and dislocation-mediated two-dimensional melting, using a combination of Landau and continuum elasticity theory. If dislocations are excluded, coupling to the elastic degrees of freedom leads to mean-field critical exponents. When dislocations are allowed, modified elastic constants lead to a phase buried in the solid state near the critical point. Consistent with a proposal of Bladon and Frenkel [P. Bladon and D. Frenkel, Phys. Rev. Lett. 74, 2519 (1995)], we find an intervening hexatic phase near the critical point of the first-order isostructural transition line. Very close to the critical point, a transition from the hexatic phase to a modulated-bond-angle state is possible. Ising transitions in symmetrically confined two-dimensional colloidal crystals with attractive wall potentials require a different model free energy, which we also discuss.
引用
收藏
页码:2560 / 2570
页数:11
相关论文
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