Shape-selective growth, patterning, and alignment of cubic nanostructured crystals via self-assembly

This paper reports the preparation of cubically ordered, self-assembled nanostructural crystals on micropatterned surfaces. Large ordered arrays of octahedral crystals were formed on substrates with triangular-shaped micropatterns that match the shape of the 1111 surface morphology of the crystals, Many crystals became self-aligned in X, Y, and Zorientations through the interaction with the matching micropatterns. However, line micropatterns did not produce such well-defined crystals and crystal alignment. This work is among the first examples to show 3D crystal alignment independent of the long rodlike micellar structure that is characteristic of the hexagonal phases. Significantly, it also suggests that the geometry of the underline patterns has a large effect on the crystal morphology and orientation. We hope that these results will be helpful in developing microdevices based on self-assembled nanoscale materials.