Pursuing colloidal diamonds

Abstract

The endeavor to selectively fabricate cubic diamond is challenging due to the formation of competing phases such as its hexagonal polymorph or others possessing similar free energy. The necessity to...

Interplay between the Formation of Colloidal Clathrate and Cubic Diamond Crystals

“…Surprisingly, an increase of the external field to ξ = 0.4 leads to the formation of sII clathrate networks for the majority of replicas; however, for 2 out of 10, we found similar CD/HD hybrids (Figure S4 in the Supporting Information). Further increase of the confining energy leads to similar effects, as reported in our previous article . We have observed the emergence of the CD crystals and that the stacking hybrids are not perpendicular to the z -axis but tilted for about 45° (ξ = 0.6, Figure d) or that only the CD polymorph is formed (ξ = 0.8, Figure e).…”

“…In such a way, the emergence of the stacking hybrids is avoided and the selectivity in the formation of the CD can be achieved. The same effect has already been demonstrated for tetrahedral patchy particles with wider patches …”

“…Further increase of the confining energy leads to similar effects, as reported in our previous article. 34 We have observed the emergence of the CD crystals and that the stacking hybrids are not perpendicular to the z-axis but tilted for about 45°(ξ = 0.6, Figure 3d) or that only the CD polymorph is formed (ξ = 0.8, Figure 3e). This effect is observed for the majority of replicas; however, some exceptions have also been found for this system size (Figure S4 in the Supporting Information).…”

“…The same effect has already been demonstrated for tetrahedral patchy particles with wider patches. 34 To further prove the metastability of clathrate networks as well as to demonstrate that the frustrations present in a smaller system result in defects of the growing networks, we have performed simulations for a larger system size, composed of N = 16,129 patchy particles. For this system size and with ξ = 0.4, only 2 out of 10 replicas exhibited the formation of only sII clathrate cages, indicating that emerging frustrations can be alleviated with sufficiently large system sizes.…”

“…Therefore, in this article, we continue the investigation of tetrahedral patchy particles, for which we have recently 34 shown that the presence of sufficiently strong external confining potential leads to the selective formation of a CD polymorph even in one-component system. We show that, similar to previous studies, 10 controlling the valency of directional interactions is insufficient for the selective formation of desired crystalline structures in the bulk and the emergence of empty sII clathrate cages, and interwoven stacking diamonds are observed for narrow patches in a one-bond-per-patch regime.…”