%0 Journal Article %K Transmission electron microscopy %K Room temperature %K Synthesis %K Phase transitions %K Nanocrystal %K Materials properties %K Polarization %K Ferroelectric materials %K Nanocrystals %K Low temperature %K Unclassified drug %K Article %K Chemical structure %K Phase transition %K Polar phase %K Particle Size %K Ferroelectric distortion %K Germanium telluride %K Germanium %K Controlled synthesis %K Crystalline phase transition %K Low temperatures %K Monodomains %K Multiple polarizations %K Nanoscale system %K Non-volatile memory application %K Phase change process %K Polarization domain %K Rhombohedral structures %K Amorphous materials %K Colloid %A M.J Polking %A H Zheng %A Ramamoorthy Ramesh %A A.P Alivisatos %B Journal of the American Chemical Society %D 2011 %G eng %P 2044-2047 %R 10.1021/ja108309s %T Controlled synthesis and size-dependent polarization domain structure of colloidal germanium telluride nanocrystals %V 133 %X Germanium telluride (GeTe) exhibits interesting materials properties, including a reversible amorphous-to-crystalline phase transition and a room-temperature ferroelectric distortion, and has demonstrated potential for nonvolatile memory applications. Here, a colloidal approach to the synthesis of GeTe nanocrystals over a wide range of sizes is demonstrated. These nanocrystals have size distributions of 10-20% and exist in the rhombohedral structure characteristic of the low-temperature polar phase. The production of nanocrystals of widely varying sizes is facilitated by the use of Ge(II) precursors with different reactivities. A transition from a monodomain state to a state with multiple polarization domains is observed with increasing size, leading to the formation of richly faceted nanostructures. These results provide a starting point for deeper investigation into the size-scaling and fundamental nature of polar-ordering and phase-change processes in nanoscale systems. © 2011 American Chemical Society.