Search Results - (Author, Cooperation:C. B. Murray)
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1Latest Papers from Table of Contents or Articles in PressM. Cargnello ; A. C. Johnston-Peck ; B. T. Diroll ; E. Wong ; B. Datta ; D. Damodhar ; V. V. Doan-Nguyen ; A. A. Herzing ; C. R. Kagan ; C. B. Murray
Nature Publishing Group (NPG)
Published 2015Staff ViewPublication Date: 2015-08-28Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsPublished by: -
2Latest Papers from Table of Contents or Articles in PressM. Cargnello ; V. V. Doan-Nguyen ; T. R. Gordon ; R. E. Diaz ; E. A. Stach ; R. J. Gorte ; P. Fornasiero ; C. B. Murray
American Association for the Advancement of Science (AAAS)
Published 2013Staff ViewPublication Date: 2013-07-23Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
3Latest Papers from Table of Contents or Articles in PressJ. H. Choi ; H. Wang ; S. J. Oh ; T. Paik ; P. Sung ; J. Sung ; X. Ye ; T. Zhao ; B. T. Diroll ; C. B. Murray ; C. R. Kagan
American Association for the Advancement of Science (AAAS)
Published 2016Staff ViewPublication Date: 2016-04-29Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
4Articles: DFG German National LicensesStaff View
ISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: High temperature, solution phase reduction of cobalt chloride in the presence of stabilizing agents was employed to produce magnetic colloids (ferrofluids) of cobalt nanocrystals. We systematically synthesized and isolated nearly monodisperse nanocrystal samples ranging in size from 2 to 11 nm while maintaining better than a 7% std. dev. in diameter. As synthesized cobalt particles are each a single crystal with a complex cubic structure related to the beta phase of elemental manganese (ε-Co). Annealing the nanocrystals at 300 °C converts them quantitatively to the more common hexagonal-close-packed crystal form. Deposition of these uniform cobalt particles on solid substrates by evaporation of the carrier solvent results in the spontaneous assembly of two-dimensional and three-dimensional magnetic superlattices (colloidal crystals). A combination of x-ray powder diffraction, transmission electron microscopy, and superconducting quantum interference device magnetometry were used to characterize both the dispersed nanocrystals and the assembled superlattices. © 1999 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesDanek, M. ; Jensen, K. F. ; Murray, C. B. ; Bawendi, M. G.
Woodbury, NY : American Institute of Physics (AIP)
Published 1994Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: A novel technique combining electrospray and organometallic chemical vapor deposition (OMCVD) has been developed for the synthesis of new II–VI quantum dot composites. CdSe nanocrystals (quantum dots) of selected size are dispersed in a pyridine/acetonitrile mixture. The nanocrystals are transferred by electrospray into the growth zone of an OMCVD reactor and codeposited on a ZnSe matrix grown from hydrogen selenide and diethyl zinc. Composites consisting of CdSe nanocrystals and an amorphous or polycrystalline ZnSe matrix have been deposited on glass substrates at temperatures of 150–250 °C. Room-temperature absorption and photoluminescence spectra show optical transitions characteristic of the initial nanocrystal dispersions. The emission wavelength may be tuned in a broad spectral region by incorporating nanocrystals of varying sizes. The composites have been characterized by Auger electron spectroscopy, high resolution transmission electron microscopy, and scanning transmission electron microscopy. © 1994 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesBecerra, L. R. ; Murray, C. B. ; Griffin, R. G. ; Bawendi, M. G.
College Park, Md. : American Institute of Physics (AIP)
Published 1994Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: Room temperature 31P magic angle sample spinning (MAS) nuclear magnetic resonance (NMR) is used to study the phosphine chalconide species coordinating the surface of CdSe nanocrystallites. Two surface species are identified: trioctylphosphine oxide (TOPO) and trioctylphosphine selenide (TOPSe). The TOPO coordinates Cd surface sites while trioctylphosphine (TOP) coordinates Se to produce surface TOPSe species. Chemical removal of TOPSe linkages produces CdSe nanocrystallites passivated exclusively with TOPO. A double resonance experiment (31P and 77Se) characterizes the TOPSe species. Quantitative studies indicate coordination to nearly all surface Cd atoms and allows the development of a model for the morphology of an average crystallite surface.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesSacra, A. ; Norris, D. J. ; Murray, C. B. ; Bawendi, M. G.
College Park, Md. : American Institute of Physics (AIP)
Published 1995Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: We use Stark spectroscopy to examine the nature of the excited states of CdSe nanocrystallites. The Stark spectra we obtain are in the small coupling limit in which the changes induced by the electric field to the absorption spectrum are small compared to the transition linewidths. Within this limit, we theoretically examine the dependence of the line shape of Stark difference spectra on the linewidth of the transitions involved. For systems such as CdSe nanocrystallites, which have overlapping transitions coupled by the electric field, we find that the usual association of derivatives of absorption features with dipole moments and polarizabilities is problematic. We show that the Stark absorption spectrum of the CdSe nanocrystallites can be explained by polarizable and delocalized nonpolar excited states. © 1995 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesMattoussi, H. ; Cumming, A. W. ; Murray, C. B. ; Bawendi, M. G. ; Ober, R.
College Park, Md. : American Institute of Physics (AIP)
Published 1996Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: We use x-ray scattering at small angles (SAXS) to study interparticle interactions in dilute dispersions of CdSe nanocrystallite particles. In particular, we probe the dependence of these interactions on a few key parameters, including the nature of the cap molecules attached to the surface of the particles and the solvent. Alkyl capped nanocrystallites with relatively long hydrocarbon chains are stable in a range of solvents. Nanocrystallites capped with smaller molecules show attractive interparticle interactions. Existence of association (e.g., dimers and trimers) in dispersions characterized by attractive interactions is observed in the scattering data for pyridine capped particles. © 1996 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Eggs and alevins from 21 families of pink salmon, Oncorhynchus gorbuscha, from five odd-year broodline stocks spawning in southern British Columbia were incubated under controlled water temperatures of 4° C, 8° C and 12° C. There were significant differences in egg survival among stocks and among families within stocks at all incubation temperatures, but the differences were greatest at 4° C. Alevin survival was at least 97% for each stock at each temperature. The most northern spawning stocks had higher egg survival at 4° C than did the others. Hatching time of the alevins and emergence time of the fry were similar for all five stocks. Alevins hatching at 8° C were longer than those hatching at 4°C or 12°C, but there were no stock differences in alevin length or tissue weight. Stocks with larger eggs produced alevins of greater total weight and more yolk. Emergent fry from Vancouver Island stocks had the greatest tissue weight at 12° C, but Fraser River fry were heaviest at 8° C. There were significant differences among families within stocks for alevin and fry size parameters, suggesting that family variation should be accounted for in studies of salmonid developmental biology.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: We examined regional and latitudinal variation in fecundity and egg weight for five species of Pacific salmon (Oncorhynchus) along the Pacific coast of North America. Data were examined for 24 chum salmon, 15 pink salmon, 34 sockeye salmon, 44 chinook salmon, and 40 coho salmon populations from published sources, unpublished Canadian hatchery records, our own laboratory investigations, and other unpublished sources. Substantial regional variation in fecundity and egg weight was observed, with salmon on the Queen Charlotte Islands and Vancouver Island in British Columbia generally having lower fecundity and larger egg size than nearby mainland populations. The relative distance of freshwater migration to the spawning grounds generally had a marked effect on both fecundity and egg size, with populations spawning in the upper portions in the drainages of large rivers like the Fraser River in British Columbia having reduced fecundity and egg size compared with coastal spawning populations. Fecundity was generally higher and egg size generally lower in more northern populations of sockeye, chinook, and coho salmon compared with southern ones. We suggest that egg size tends to be lower in northern populations of some species as a result of increased fecundity due to their older ages at maturity and a limited amount of energy that can be expended on egg production.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesRedl, F. X. ; Cho, K.-S. ; Murray, C. B. ; O'Brien, S.
[s.l.] : Macmillian Magazines Ltd.
Published 2003Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] Recent advances in strategies for synthesizing nanoparticles—such as semiconductor quantum dots, magnets and noble-metal clusters—have enabled the precise control of composition, size, shape, crystal structure, and surface chemistry. The distinct properties of the resulting ...Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 1434-6079Keywords: 73.20.Dx ; 73.20.At ; 63.20.KrSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract The surface electronic properties of CdSe nanocrystallites have been probed using low temperature and Zeeman spectroscopies. Fluorescence line narrowed spectra show dramatic changes between 1.75 and 10 K and also as a function of applied magnetic field. These effects are attributed to the localization of the photogenerated charge carriers on the surface. A simple model has been constructed to calculate the charge distribution within the nanocrystallite.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 1434-6079Keywords: 36.40.+d ; 73.20.Dx ; 63.20.DjSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract We use low temperature (10K) optical hole-burning and fluorescence line narrowing spectroscopy to investigate the electronic properties of CdSe nanocrystallites (quantum dots) as a function of crystallite diameter (20–80Å). We discuss how the homogeneous linewidth of the HOMO-LUMO transition, the energy shift between the absorbing and emitting state, and the LO phonon frequency vary with nanocrystallite size.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 1434-6079Source: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract A methodology for the production of II–VI semiconductor nanocrystallites employing organometallic precursors has been developed. The rapid pyrolysis of reagents in a coordinating solvent provides temporally discrete nucleation. Subsequent controlled growth allows the production of macroscopic quantities of nanocrystallites with consistent structure, surface derivatization and a high degree of monodispersity. The samples produced are structurally characterized with a combination of X-ray and Electron Beam based techniques.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesIbottson, F. ; Brearley, H. ; Fried ; Murray, C. B. ; Maury, G. P. ; Lidholm, Hj. ; Ramovino, C.
Springer
Published 1905Staff ViewISSN: 1618-2650Source: Springer Online Journal Archives 1860-2000Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: