8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Wed 711:10-14:00P5.119Phase behavior of colloidal hard superballs: fromoctahedra to cubesRan Ni, 1 Anjan Gantapara, 1 and Marjolein Dijkstra 11 Utrecht University, Princetonplein 5, 3584CC, Utrecht, NetherlandsRecent breakthroughs in particle synthesis have produced a spectacular variety of anisotropicbuilding blocks. The morphology plays an important role in the self-assembly of particles. Inthis work, we use Monte Carlo simulations in combination with full free energy calculations tostudy the phase behavior of colloidal hard superballs whose interior is de?ned by the inequality|x| 2q + |y| 2q + |z| 2q ≤ 1 where q is the deformation parameter. The shape of superballs interpolatesbetween octahedra (q = 0.5) and cubes(q = ∞) via spheres(q = 1). When 0.5 ≤ q ≤ 1, wefind that there is a deformed body-centered-cubic (bcc) crystal phase stable when approaching theclose packing limit. At relatively lower pressure stable plastic bcc and face-centered-cubic(fcc)crystal phases exist. Moreover, for cube-like superballs(1 < q < ∞), there are C 1 -like and C 0 -likecrystals stable at high pressure for different q [1]. At relatively lower pressure, a fcc plastic crystalbecomes stable. When q = ∞, the C 1 phase approaches simple cubic crystal.[1] Y. Jiao, F. H. Stillinger, and S. Torquato, Phys. Rev. E 79, 041309 (2009).119