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Controlling Size-Induced Phase Transformations Using Chemically Designed Nanolaminates


  • This work was supported by the NSF through CCI grant CHE-1102637, and grant MRI 0923577 provided equipment used in this investigation. M.B. acknowledges support from the NSF under grant DMR 0907049. S.R. and W.S.N. acknowledge support from ONR Award No. N000141110193. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. The authors thank J. Karapatrova and D. Robinson for their assistance in collection of the synchrotron X-ray diffraction data, and C. Heideman and D. Moore for useful discussions.


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By dimensionally constraining crystalline layers in a non-epitaxial intergrowth, nanocrystal ensembles with well-defined and precisely controlled size are prepared. Synchrotron X-ray diffraction, electron microscopy, and density functional theory show that a size-induced second-order structural transition allows the crystal structure of a layered semiconductor (SnSe) to be continuously tuned by controlling the thickness of the individual layers.