Franzini Stefano, Reatto Luciano, Pini Davide
Dipartimento di Fisica "A. Pontremoli", Università di Milano, Via Celoria 16, 20133 Milano, Italy.
Soft Matter. 2021 Dec 22;18(1):186-197. doi: 10.1039/d1sm01257f.
We investigate the phase diagram of a fluid of hard-core disks confined to the surface of a sphere and whose interaction potential contains a short-range attraction followed by a long-range repulsive tail (SALR). Based on previous work in the bulk we derive a stability criterion for the homogeneous phase of the fluid, and locate a region of instability linked to the presence of a negative minimum in the spherical harmonics expansion of the interaction potential. The inhomogeneous phases contained within this region are characterized using a mean-field density functional theory. We find several inhomogeneous patterns that can be separated into three broad classes: cluster crystals, stripes, and bubble crystals, each containing topological defects. Interestingly, while the periodicity of inhomogeneous phases at large densities is mainly determined by the position of the negative minimum of the potential expansion, the finite size of the system induces a richer behavior at smaller densities.
我们研究了局限于球体表面的硬核圆盘流体的相图，该流体的相互作用势包含短程吸引随后是长程排斥尾（SALR）。基于之前在体相中的工作，我们推导了该流体均匀相的稳定性判据，并确定了一个与相互作用势的球谐展开中负最小值的存在相关的不稳定区域。使用平均场密度泛函理论对该区域内的非均匀相进行了表征。我们发现了几种非均匀模式，可分为三大类：团簇晶体、条纹和泡状晶体，每一类都包含拓扑缺陷。有趣的是，虽然大密度下非均匀相的周期性主要由势展开的负最小值位置决定，但系统的有限尺寸在较小密度下会引发更丰富的行为。
