The formation of CdS quantum dots and Au nanoparticles

AbstractWe report on microsecond-resolved in-situ SAXS experiments of the early nucleation and growth behavior of both cadmium sulfide (CdS) quantum dots in aqueous solution including the temperature dependence and of gold (Au) nanoparticles. A novel free-jet setup was developped to access reaction times as early as 20 μs. As the signal in particular in the beginning of the reaction is weak the containment-free nature of this sample environment prooved crucial. The SAXS data reveal a two-step pathway with a surprising stability of a structurally relaxed cluster with a diameter of about 2 nm. While these develop rapidly by ionic assembly, a further slower growth is attributed to cluster attachment. WAXS diffraction confirms, that the particles at this early stage are not yet crystalline. This growth mode is confirmed for a temperature range from 25°C to 45°C. An energy barrier for the diffusion of primary clusters in water of 0.60 eV was experimentally observed in agreement with molecular simulations. To access reaction times beyond 100 ms, a stopped-drop setup -again contaiment- free is introduced. SAXS experiments on the growth of Au nanoparticles on an extended time scale provide a much slower growth with one population only. Further, the influence of ionizing X-ray radiation on the Au particle fromation and growth is discussed.

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The Structural Characteristics Features of the Nanocomposite Systems of CdS Quantum Dots in the Gel Matrix Obtained by the Method of Small-Angle X-Ray Scattering

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.213.216 ◽

2014 ◽

Vol 213 ◽

pp. 216-221

Author(s):

Anna N. Galkina ◽

Alexander A. Sergeev

Keyword(s):

Quantum Dots ◽

Small Angle ◽

Structural Characteristics ◽

Data Interpretation ◽

Cds Quantum Dots ◽

Particle Structure ◽

Saxs Data ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

The strucrture of CdS quantum dots 0,3% (mass), stabilized by the solution of the mercaptosuccinic acid in the gel matrix 50% THEOS is investigated by small-angle X-ray scattering (SAXS). Application of modern methods of SAXS data interpretation, including procedure of ab initio modeling of particle structure, allowed us for the to reveal structural organization of both individual nanoparticles and of their clusters incorporated in the polymer matrix. As a result, the shape, size, and size distribution of the obtained nanoparticles and their clusters depended on the structure of the gel matrix used as a formation medium.

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In Situ Testing and X Rays Radiation Effects of Pt/Bi3.15Nd0.85Ti3O12/Pt Ferroelectric Capacitors

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.712-715.293 ◽

2013 ◽

Vol 712-715 ◽

pp. 293-297

Author(s):

Li Li

Keyword(s):

Radiation Effects ◽

Hysteresis Loops ◽

Electrical Performance ◽

Hysteresis Curve ◽

X Rays ◽

Shanghai Synchrotron Radiation Facility ◽

X Ray ◽

In The Beginning ◽

Ferroelectric Capacitors

Pt/Bi3.15Nd0.85Ti3O12(BNT)/Pt ferroelectric capacitors were monitored using in situ X-ray irradiation with 10 keV at BL14B1 beamline (Shanghai Synchrotron Radiation Facility). BL14B1 combined with a ferroelectric analyzer enabled measurements in situ of electrical performance. The hysteresis curve (PE) of distortion depended on the polarization during irradiation, but the diffracted intensities of the (117) peak did not change in the beginning. ThePEcurve had a negligible change from 2.09×109Gy to 4.45×109Gy. Finally, bothPrandPr+very rapidly increased, but the intensities of (117) decreased. The hysteresis loops were remarkably deformed at the maximum total dose of 4.87×109Gy.

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In Situ Investigation of the Early-Stage Growth of Nanoporous Alumina

Journal of Nanomaterials ◽

10.1155/2018/6428271 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9

Author(s):

Thérèse Gorisse ◽

Ludovic Dupré ◽

Marc Zelsmann ◽

Alina Vlad ◽

Alessandro Coati ◽

...

Keyword(s):

Early Stage ◽

Grazing Incidence ◽

Alumina Layer ◽

Nanoporous Alumina ◽

X Ray ◽

X Ray Scattering ◽

In Situ Investigation ◽

Low X ◽

X Ray Absorption

We report the successful use of in situ grazing incidence small-angle X-ray scattering to follow the anodization of aluminum. A dedicated electrochemical cell was designed and developed for this purpose with low X-ray absorption, with the possibility to access all azimuthal angles (360°) and to remotely control the temperature of the electrolyte. Three well-known fabrication techniques of nanoporous alumina, i.e., single, double, and pretextured, were investigated. The differences in the evolution of the scattering images are described and explained. From these measurements, we could determine at which moment the pores start growing even for very short anodization times. Furthermore, we could follow the thickness of the alumina layer as a function of the anodization time by monitoring the period of the Kiessig fringes. This work is aimed at helping to understand the different steps taking place during the anodization of aluminum at the very early stages of nanoporous alumina formation.

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Study of CdSe/CdS quantum dots in solutions and gels by small-angle X-ray scattering

Journal of Surface Investigation X-ray Synchrotron and Neutron Techniques ◽

10.1134/s1027451011020182 ◽

2011 ◽

Vol 5 (1) ◽

pp. 126-133 ◽

Cited By ~ 4

Author(s):

N. B. Simonova ◽

F. V. Tuzikov ◽

R. N. Khramov ◽

N. A. Tuzikova ◽

M. F. Tuzikov ◽

...

Keyword(s):

Quantum Dots ◽

Small Angle ◽

Cds Quantum Dots ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

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GROWTH OF OXIDE LAYER ON GERMANIUM (011) SUBSTRATE UNDER DRY AND WET ATMOSPHERES

Surface Review and Letters ◽

10.1142/s0218625x99001141 ◽

1999 ◽

Vol 06 (06) ◽

pp. 1053-1060 ◽

Cited By ~ 11

Author(s):

N. TABET ◽

J. AL-SADAH ◽

M. SALIM

Keyword(s):

Simple Model ◽

Oxide Film ◽

Growth Kinetics ◽

Photoelectron Spectroscopy ◽

Early Stage ◽

X Ray ◽

Apparent Thickness ◽

Different Temperatures ◽

Kinetics Of

X-ray Photoelectron Spectroscopy (XPS) has been used to investigate the oxidation of (011) Ge substrates. The sample surfaces were CP4-etched, then annealed in situ, at different temperatures, for various durations. Dry and wet atmospheres were used. The oxidation rate during the early stage was increased by the presence of moisture in the atmosphere. A simple model was used to define and determine an apparent thickness of the oxide film from XPS measurements. The time dependence of the apparent thickness is consistent with a partial coverage of the surface by oxide islands. The growth kinetics of the oxide islands obeys a nearly cubic law.

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In situ magnetic and electronic investigation of the early stage oxidation of Fe nanoparticles using X-ray photo-emission electron microscopy

Physical Chemistry Chemical Physics ◽

10.1039/c4cp02725f ◽

2014 ◽

Vol 16 (48) ◽

pp. 26624-26630 ◽

Cited By ~ 14

Author(s):

C. A. F. Vaz ◽

A. Balan ◽

F. Nolting ◽

A. Kleibert

Keyword(s):

Electron Microscopy ◽

Chemical Composition ◽

Iron Nanoparticles ◽

Early Stage ◽

Photoemission Electron Microscopy ◽

X Ray ◽

Emission Electron ◽

Fe Nanoparticles ◽

Photoemission Electron

In situX-ray photoemission electron microscopy reveals the evolution of chemical composition and magnetism of individual iron nanoparticles during oxidation.

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Transparent Medium Embedded with CdS Quantum Dots for X‐Ray Imaging

Advanced Optical Materials ◽

10.1002/adom.202101607 ◽

2021 ◽

pp. 2101607

Author(s):

Zhaohui Fang ◽

Haitao Tang ◽

Ze Yang ◽

Hao Zhang ◽

Qingpeng Peng ◽

...

Keyword(s):

Quantum Dots ◽

Transparent Medium ◽

Cds Quantum Dots ◽

X Ray ◽

X Ray Imaging

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A Combined Experimental and Theoretical Study of Lithiation Mechanism in ZnFe2O4 Anode Materials

MRS Advances ◽

10.1557/adv.2018.305 ◽

2018 ◽

Vol 3 (14) ◽

pp. 773-778 ◽

Cited By ~ 4

Author(s):

Lei Wang ◽

Alison McCarthy ◽

Kenneth J. Takeuchi ◽

Esther S. Takeuchi ◽

Amy C. Marschilok

Keyword(s):

Early Stage ◽

Deep Understanding ◽

Lithium Ion ◽

Oxidation Products ◽

Ex Situ ◽

Theoretical Modelling ◽

X Ray Diffraction ◽

X Ray ◽

X Ray Absorption

ABSTRACTZnFe2O4 (ZFO) represents a promising anode material for lithium ion batteries, but there is still a lack of deep understanding of the fundamental reduction mechanism associated with this material. In this paper, the complete visualization of reduction/oxidation products irrespective of their crystallinity was achieved experimentally through a compilation of in situ X-ray diffraction, synchrotron based powder diffraction, and ex-situ X-ray absorption fine structure data. Complementary theoretical modelling study further shed light upon the fundamental understanding of the lithiation mechanism, especially at the early stage from ZnFe2O4 up to LixZnFe2O4 (x = 2).

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