A Ti–46Al(at.%) polysynthetically twinned alloy, which contained a characteristic lamellar spacing of k 1⁄4 1:3 lm, was converted to a polycrystalline fully-lamellar microstructure with k 1⁄4 19:9 nm using an a-phase solution treatment followed by a2 þ c aging. Tensile experiments, performed on microsamples extracted from within single grains of the polycrystalline material, illustrated that ul...

The molecules in lyotropic membranes are typically aligned with the surface normal. When these molecules are chiral, there is a tendency for the molecular direction to twist. These competing effects can reach a compromise by producing helicoidal defects in the membranes. Unlike thermotropic smectics, the centers of these defects are hollow and thus their energy cost comes from the line energy o...

We introduce a model constitutive law for the dissipative stress tensor of lamellar phases to account for low frequency and long wavelength flows. Given the uniaxial symmetry of these phases, we argue that the stress tensor must be the same as that of a nematic but with the local order parameter being the slowly varying lamellar wavevector. This assumption leads to a dependence of the effective...

Growth of CdS was studied in three different liquid crystalline phases demonstrating the versatility of liquid crystal templating of inorganic solids. Semiconductor growth in a hexagonal liquid crystal yielded a nanostructure with hexagonal symmetry, a lamellar liquid crystal yielded a lamellar nanostructure, and a cubic liquid crystal (consisting of spherical micelles) yielded a hollow, spheri...

We identify a finite wave-number instability of a 90 degrees tilt grain boundary in three-dimensional lamellar phases which is absent in two-dimensional configurations. Both a stability analysis of the slowly varying amplitude or envelope equation for the boundary, and a direct numerical solution of an order parameter model equation are presented. The instability mode involves two-dimensional p...

The phase-field method has become the method of choice for simulating microstructure formation during solidification. Recent progress, both on the formulation of the model and on the numerical implementation, makes it now possible to simulate quantitatively the evolution of complex microstructures in three dimensions. This is illustrated by simulations of eutectic coupled growth. The morphologi...