A porous matrix for studying the optical properties of systems of close-packed quantum dots

2014 ◽  
Vol 81 (8) ◽  
pp. 449 ◽  
Author(s):  
P. S. Parfenov ◽  
A. P. Litvin ◽  
E. V. Ushakova ◽  
A. V. Veniaminov ◽  
A. V. Fedorov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Porous Matrix

PbS Quantum Dots in a Porous Matrix: Optical Characterization

2013 ◽  
Vol 117 (23) ◽  
pp. 12318-12324 ◽  
Author(s):  
Aleksandr P. Litvin ◽  
Peter S. Parfenov ◽  
Elena V. Ushakova ◽  
Anatoly V. Fedorov ◽  
Mikhail V. Artemyev ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Characterization ◽  
Porous Matrix ◽  
Pbs Quantum Dots

Optical properties and aging of PbS quantum dots embedded in a porous matrix

2013 ◽  
Author(s):  
Aleksandr P. Litvin ◽  
Peter S. Parfenov ◽  
Elena V. Ushakova ◽  
Anatoly V. Fedorov ◽  
Mikhail V. Artemyev ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Porous Matrix ◽  
Pbs Quantum Dots

Photoconductivity of structures based on the SnO2 porous matrix coupled with core-shell CdSe/CdS quantum dots

2013 ◽  
Vol 103 (13) ◽  
pp. 133115 ◽  
Author(s):  
K. A. Drozdov ◽  
V. I. Kochnev ◽  
A. A. Dobrovolsky ◽  
A. V. Popelo ◽  
M. N. Rumyantseva ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Porous Matrix ◽  
Core Shell ◽  
Cds Quantum Dots

Luminescence and morphology study of PbS quantum dots in a porous matrix

2014 ◽  
Author(s):  
P.S. Parfenov ◽  
A.P. Litvin ◽  
E.V. Ushakova ◽  
A.V. Fedorov ◽  
A.V. Baranov
Keyword(s):  
Quantum Dots ◽  
Porous Matrix ◽  
Morphology Study ◽  
Pbs Quantum Dots

scholarly journals Characterizing InGaAs/GaAs quantum dots using low-kV FESEM imaging and EDS analysis at the nanometer scale

2016 ◽  
Vol 22 (S3) ◽  
pp. 1586-1587 ◽  
Author(s):  
Fang Zhou ◽  
Luyang Han ◽  
Simon Burgess ◽  
Xiaobing Li
Keyword(s):  
Quantum Dots ◽  
Nanometer Scale ◽  
Eds Analysis

Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
Author(s):  
Zdenek Sekanina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Interplanetary Space ◽  
Porous Matrix ◽  
Maximum Diameter ◽  
Expansion Velocity ◽  
Solid Constituent ◽  
Meteoric Material ◽  
Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

A correlation of CL emissions from Penrith sandstone with elemental distributions obtained by simultaneous SEM-CL and EDS analysis

1995 ◽  
Vol 53 ◽  
pp. 392-393
Author(s):  
Paul J. Wright
Keyword(s):  
Optical Microscope ◽  
Electron Gun ◽  
High Electron ◽  
Collection System ◽  
Electron Hole ◽  
Depositional Processes ◽  
Eds Analysis ◽  
Distribution Mapping ◽  
Backscattered Electron ◽  
Electron Imaging

Most industrial and academic geologists are familiar with the beautiful red and orange cathodoluminescence colours produced by carbonate minerals in an optical microscope with a cold cathode electron gun attached. The cement stratigraphies interpreted from colour photographs have been widely used to determine the post depositional processes which have modified sedimentary rock textures.However to study quartzose materials high electron densities and kV's are necessary to stimulate sufficient emission. A scanning electron microscope with an optical collection system and monochromator provides an adequate tool and gives the advantage of providing secondary and backscattered electron imaging as well as elemental analysis and distribution mapping via standard EDS/WDS facilities.It has been known that the incorporation of many elements modify the characteristics of the CL emissions from geological materials. They do this by taking up positions between the valence and conduction band thus providing sites to assist in the recombination of electron hole pairs.

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

Electron-Probe Quantitative Energy-Dispersive Analysis of Trace Magnesium Concentrations in Ag-Mg Alloys

1996 ◽  
Vol 54 ◽  
pp. 510-511
Author(s):  
R. B. Marinenko
Keyword(s):  
Electron Probe ◽  
Energy Dispersive Spectrometry ◽  
Mg Alloys ◽  
Energy Dispersive ◽  
Energy Dispersive Analysis ◽  
High Tc ◽  
Alloy Wire ◽  
High Tc Superconductor ◽  
Eds Analysis ◽  
Superior Mechanical Properties

Internally oxidized Ag-Mg alloys are used as sheaths for high Tc superconductor wires because of their superior mechanical properties. The preparation and characteristics of these materials have been reported. Performance of the sheaths depends on the concentration of the magnesium which generally is less than 0.5 wt. percent. The purpose of this work was to determine whether electron probe microanalysis using energy dispersive spectrometry (EDS) could be used to quantitate three different Ag-Mg alloys. Quantitative EDS analysis can be difficult because the AgL escape peak occurs at the same energy (1.25 keV) as the Mg Kα peak. An EDS spectrum of a Ag-Mg alloy wire is compared to a pure Ag spectrum in Fig. 1.

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