Journal ArticleDOI
Size dependence of structural metastability in semiconductor nanocrystals
TLDR
The kinetics of a first-order, solid-solid phase transition were investigated in the prototypical nanocrystal system CdSe as a function of crystallite size and general rules that may be of use in the discovery of new metastable phases are suggested.Abstract:
The kinetics of a first-order, solid-solid phase transition were investigated in the prototypical nanocrystal system CdSe as a function of crystallite size. In contrast to extended solids, nanocrystals convert from one structure to another by single nucleation events, and the transformations obey simple unimolecular kinetics. Barrier heights were observed to increase with increasing nanocrystal size, although they also depend on the nature of the nanocrystal surface. These results are analogous to magnetic phase transitions in nanocrystals and suggest general rules that may be of use in the discovery of new metastable phases.read more
Citations
More filters
Journal ArticleDOI
Cation exchange reactions in ionic nanocrystals.
Dong Hee Son,Steven M. Hughes,Steven M. Hughes,Yadong Yin,Yadong Yin,A. Paul Alivisatos,A. Paul Alivisatos +6 more
TL;DR: A critical size has been identified below which the shapes of complex nanocrystals evolve toward the equilibrium shape with lowest energy during the exchange reaction, above which the anion sublattice remains intact and the basic shapes of the initial nanocry crystals are retained throughout the cation exchange.
Journal ArticleDOI
Shape Transition of Germanium Nanocrystals on a Silicon (001) Surface from Pyramids to Domes
Gilberto Medeiros-Ribeiro,Alexander Bratkovski,Theodore I. Kamins,Douglas A. A. Ohlberg,R. Stanley Williams +4 more
TL;DR: In situ scanning tunneling microscopy revealed that the smaller square-based pyramids transform abruptly during growth to significantly larger multifaceted domes, and that few structures with intermediate size and shape remain.
Journal ArticleDOI
Size effects in the Raman spectra of TiO2 nanoparticles
TL;DR: In this paper, the authors investigated the relationship between the particle size and the Raman bands of TiO 2 nanoparticles using transmission electron microscopy (TEM), X-ray absorption near edge structure (XANES), extended Xray absorption fine structure (EXAFS), and Raman spectroscopy.
Journal ArticleDOI
Lithographic Imaging Techniques for the Formation of Nanoscopic Features
Journal ArticleDOI
Shape-Memory Nanopores Induced in Coordination Frameworks by Crystal Downsizing
Yoko Sakata,Shuhei Furukawa,Mio Kondo,Kenji Hirai,Nao Horike,Yohei Takashima,Hiromitsu Uehara,Nicolas Louvain,Mikhail Meilikhov,Takaaki Tsuruoka,Seiji Isoda,Wataru Kosaka,Osami Sakata,Susumu Kitagawa +13 more
TL;DR: It is demonstrated that the crystal downsizing of twofold interpenetrated frameworks of [Cu2(dicarboxylate)2(amine)]n regulates the structural flexibility and induces a shape-memory effect in the coordination frameworks.
References
More filters
Journal ArticleDOI
Synthesis and characterization of nearly monodisperse CdE (E = sulfur, selenium, tellurium) semiconductor nanocrystallites
TL;DR: In this paper, a simple route to the production of high-quality CdE (E=S, Se, Te) semiconductor nanocrystallites is presented, based on pyrolysis of organometallic reagents by injection into a hot coordinating solvent.
Journal ArticleDOI
A Mechanism of Magnetic Hysteresis in Heterogeneous Alloys
Edmund C. Stoner,E. P. Wohlfarth +1 more
TL;DR: In this paper, the effect of shape anisotropy on magnetization curves was studied for the case of ellipsoidal spheroids of revolution (e.g., ellipses of revolution).
Journal ArticleDOI
X-ray Photoelectron Spectroscopy of CdSe Nanocrystals with Applications to Studies of the Nanocrystal Surface
TL;DR: In this article, the surface composition of semiconductor nanocrystals was determined using X-ray photoelectron spectroscopy (XPS) and the core level peak positions for Cd and Se were in agreement with those of bulk CdSe.
Journal ArticleDOI
Melting in semiconductor nanocrystals.
TL;DR: Temperature-dependent electron diffraction studies on nanocrystals of CdS show a large depression in the melting temperature with decreasing size, as a larger fraction of the total number of atoms is on the surface.
Journal ArticleDOI
An Optical Fluorescence System for Quantitative Pressure Measurement in the Diamond‐Anvil Cell
TL;DR: In this article, an optical system for rapid routine pressure measurement is described which utilizes a pressure shift in the sharp R-line fluorescence spectrum of ruby or similar materials, which can be employed with suitable modification in any pressure system which has optical access.
Related Papers (5)
Size Dependence of a First Order Solid-Solid Phase Transition: The Wurtzite to Rock Salt Transformation in CdSe Nanocrystals
Shape control of CdSe nanocrystals
Xiaogang Peng,Liberato Manna,Liberato Manna,Liberato Manna,Weidong Yang,Weidong Yang,Weidong Yang,Juanita N. Wickham,Juanita N. Wickham,Juanita N. Wickham,Erik C. Scher,Erik C. Scher,Erik C. Scher,Andreas Kadavanich,Andreas Kadavanich,Andreas Kadavanich,A. P. Alivisatos,A. P. Alivisatos,A. P. Alivisatos +18 more