Non-affine heterogeneities and droplet fluctuations in an equilibrium crystalline solid

NaCl液滴沉积中光子晶体有序性和时间序列动力学的涌现

The Emergence of Photonic Crystalline Order and Time-Series Dynamics in NaCl Droplet Deposition

本研究通过多尺度实验，揭示了NaCl液滴在锗基底上蒸发时，扩散各向异性主导晶体结构尺寸，并形成一维光子晶体纳米结构，提出了NaCl等效高度作为统一度量，建立了预测蒸发液滴结晶行为的实验框架。

通过液滴外延制备的单晶InN量子点的形成机制

Formation mechanisms of single-crystalline InN quantum dots fabricated via droplet epitaxy

本研究结合实验与理论，揭示等离子体辅助分子束外延下金属液滴外延法制备单晶纤锌矿InN量子点的两阶段形成机制，对比不同衬底差异并关联其他纳米结构形成机理。

Stability of Liquid Crystalline Macroemulsions

The thermodynamic stability of emulsions of liquid crystal in water (glycerol) matrices is demonstrated for a wide range of materials and concentrations. Coalescence is prevented by an energy barrier for a topological ring defect formation in a neck between the two merging droplets. There is a characteristic size of emulsion droplets, typically tens of microns or more, controlled by the balance of elastic and anchoring energies of the liquid crystal. On removal of liquid crystallinity (by raising the temperature above $T_{ni}$ in thermotropic nematic materials, for example) the energy barriers…

Relation of vibrational excitations and thermal conductivity to elastic heterogeneities in disordered solids

In crystals, molecules thermally vibrate around the periodic lattice sites. Vibrational motions are well understood in terms of phonons, which carry heat and control heat transport. The situation is notably different in disordered solids, where vibrational excitations are not phonons and can be even localized. Recent numerical work has established the concept of elastic heterogeneity: disordered solids show inhomogeneous local mechanical response. Clearly, the heterogeneous nature of elastic properties strongly influences vibrational and thermal properties, and it is expected to be the origin …

Vapor-Liquid-Solid Growth of Monolayer MoS2 Nanoribbons

Chemical vapor deposition (CVD) of two-dimensional (2D) materials such as monolayer MoS2 typically involves the conversion of vapor-phase precursors to a solid product in a process that may be described as a vapor-solid-solid (VSS) mode. Here, we report the first demonstration of vapor-liquid-solid (VLS) growth of monolayer MoS2 yielding highly crystalline ribbon-shaped structures with a width of a few tens of nanometers to a few micrometers. The VLS growth mode is triggered by the reaction between molybdenum oxide and sodium chloride, which results in the formation of molten Na-Mo-O droplets.…

Pre-yield non-affine fluctuations and a hidden critical point in strained crystals

A crystalline solid exhibits thermally induced localised {\em non-affine} droplets in the absence of external stress. Here we show that upon an imposed shear, the size of these droplets grow until they percolate at a critical strain, well {\em below} the value at which the solid begins to yield. This critical point does not manifest in bulk thermodynamic or mechanical properties, but is {\em hidden} and reveals itself in the onset of inhomogeneities in elastic moduli, marked changes in the appearance and local properties of non-affine droplets and a sudden enhancement in defect pair concentrat…