6533b7defe1ef96bd12765d8

RESEARCH PRODUCT

Detecting Crystalline Nonequilibrium Phases on the Nanometer Scale

Ute KolbAdnan SarfrazFranziska EmmerlingKlaus RademannKlaus RademannTatiana Gorelik

subject

Materials sciencegenetic structuresHexagonal crystal systemNon-equilibrium thermodynamicsGeneral ChemistryCondensed Matter Physicslaw.inventionCrystallographyElectron diffractionlawChemical physicsLattice (order)General Materials ScienceNanometreCrystallization

description

The use of Automated electron Diffraction Tomography (ADT) is presented as a novel approach for crystallization studies at the nanometer scale for nonequilibrium phases. Here, ADT was applied to elucidate the structural identity of the recently reported hexagonal morphology of caffeine crystals, which grow only on specific surfaces. Caffeine was crystallized from solution on a specially treated TEM carbon grid. The analysis of ADT data revealed that the lattice parameters of these hexagons match those of the high temperature α- form of caffeine. Furthermore, it was observed that in this hexagonal morphology, the α-form remained stable for a prolonged period of time. The stabilization of hexagons can be interpreted in terms of enhanced interactions with the supporting surfaces.

https://doi.org/10.1021/cg300377j