Europium luminescence decay in CaF2-Ho3+, Eu2+ single crystals

1983 ◽  
Vol 38 (4) ◽  
pp. 428-430
Author(s):  
L. V. Kirilyuk
Keyword(s):  
Single Crystals ◽  
Luminescence Decay ◽  
Europium Luminescence

scholarly journals Time-resolved luminescence and excitation spectroscopy of Co-doped Gd3Ga3Al2O12 scintillating crystals

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Viktorija Pankratova ◽  
Anna P. Kozlova ◽  
Oleg A. Buzanov ◽  
Kirill Chernenko ◽  
Roman Shendrik ◽  
...  
Keyword(s):  
Single Crystals ◽  
Spectral Range ◽  
Luminescence Decay ◽  
Luminescence Spectroscopy ◽  
Bandgap Energy ◽  
Decay Kinetics ◽  
Excitation Spectra ◽  
Absorption Bands ◽  
Time Resolved ◽  
Co Doped

AbstractCerium doped Gd3Ga3Al2O12 (GGAG) single crystals as well as GGAG:Ce single crystals co-doped by divalent (Mg2+, Ca2+) and tetravalent (Zr4+, Ti4+) ions have been studied by means of time-resolved luminescence as well as the excitation luminescence spectroscopy in vacuum ultraviolet (VUV) and soft X-ray (XUV) spectral range. Tunable laser excitation was applied for time-resolved experiments in order to obtain luminescence decay curves under excitations in Ce3+, Gd3+ and excitonic absorption bands. The influence of the co-dopant ions on the Ce3+ luminescence decay kinetics is elucidated. The fastest luminescence decay was observed for the Mg2+ co-doped crystals under any excitation below bandgap energy indicating the perturbation of the 5d states of Ce3+ by Mg2+ ions. Synchrotron radiation was utilized for the luminescence excitation in the energy range from 4.5 to 800 eV. Special attention was paid to the analysis of Ce3+ excitation spectra in VUV and XUV spectral range where multiplication of electronic excitation (MEE) processes occur. Our results demonstrated that GGAG:Ce single crystals co-doped by Mg2+ ions as well as the GGAG:Ce crystal annealed in vacuum reveal the most efficient excitation of Ce3+ emission in VUV-XUV excitation range. The role of intrinsic defects in MEE processes in the co-doped as well as in the annealed GGAG:Ce single crystals is discussed.

Luminescence decay in CdIn2S4 single crystals

1983 ◽  
Vol 2 (6) ◽  
pp. 1927-1932 ◽  
Author(s):  
E. Grilli ◽  
M. Guzzi
Keyword(s):  
Single Crystals ◽  
Luminescence Decay

Luminescence decay and delayed spectra of CaWO4 single crystals

1970 ◽  
Vol 42 (2) ◽  
pp. 781-785 ◽  
Author(s):  
A. Scharmann ◽  
G. Schwarz
Keyword(s):  
Single Crystals ◽  
Luminescence Decay

SCINTILLATION DECAY IN CALCIUM TUNGSTATE

1965 ◽  
Vol 43 (11) ◽  
pp. 1925-1933 ◽  
Author(s):  
M. Sayer ◽  
W. R. Hardy
Keyword(s):  
Temperature Dependence ◽  
Single Crystals ◽  
Decay Time ◽  
Luminescence Decay ◽  
Luminescence Decay Time ◽  
Γ Radiation ◽  
Calcium Tungstate ◽  
Γ Ray ◽  
Nonradiative Centers

Measurements of the luminescence decay time have been made for a number of single crystals of calcium tungstate for excitation by cathode rays, α and γ radiation. The value of the decay time was found to depend both on the crystal used and on the nature of the excitation. For γ-ray excitation, the decay time was in the range 6.1 to 6.8 μ sec. The values obtained for cathode-ray excitation were, in general, 20–30% higher for all crystals, while for α excitation, several crystals showed no change in decay time, while others showed a decay time 20% faster. Measurements of the temperature dependence of the decay time and thermoluminescence experiments indicate that these differences in behavior can be attributed to differences in the density of energy traps and nonradiative centers in the crystal and to a rise in temperature in the excited channel.

Untersuchungen zum Problem des An- und Abklingens der Lumineszenz organischer Molekülkristalle

1967 ◽  
Vol 22 (7) ◽  
pp. 1108-1120 ◽  
Author(s):  
K. Kramer
Keyword(s):  
Single Crystals ◽  
Measuring Equipment ◽  
Molecular Crystals ◽  
Theoretical Background ◽  
Luminescence Decay ◽  
Mixed Crystals ◽  
Time Behaviour ◽  
Organic Molecular Crystals ◽  
Decay Times

The theoretical background of the time behaviour of the luminescence of organic molecular crystals is shortly discussed and a measuring equipment is described to measure the rise and the decay of luminescence intensities over four decades. Results on single crystals of anthracene, pyrene, 2,3-dimethylnaphthalene and mixed crystals at 77°K and 300°K are reported and conclusions are drawn regarding the luminescence mechanism in mixed crystals. In an appendix, some methods of measuring luminescence decay times are compared.

The Microstructure of Shock-Synthesized Diamond

1967 ◽  
Vol 25 ◽  
pp. 324-325
Author(s):  
Lucien F. Trueb
Keyword(s):  
Single Crystals ◽  
Preferred Orientation ◽  
High Magnification ◽  
Texture Pattern ◽  
Shock Process ◽  
New Type ◽  
Diffraction Diagram

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.

A New Defect in Polyethylene Single Crystals

1973 ◽  
Vol 31 ◽  
pp. 70-71
Author(s):  
E. L. Thomas ◽  
S. L. Sass
Keyword(s):  
Single Crystals ◽  
Screw Dislocation ◽  
Small Distance ◽  
Dipole Model ◽  
Dislocation Dipole ◽  
Chain Folding ◽  
Black And White ◽  
Polymer Crystal ◽  
Different Types

In polyethylene single crystals pairs of black and white lines spaced 700-3,000Å apart, parallel to the [100] and [010] directions, have been identified as microsector boundaries. A microsector is formed when the plane of chain folding changes over a small distance within a polymer crystal. In order for the different types of folds to accommodate at the boundary between the 2 fold domains, a staggering along the chain direction and a rotation of the chains in the plane of the boundary occurs. The black-white contrast from a microsector boundary can be explained in terms of these chain rotations. We demonstrate that microsectors can terminate within the crystal and interpret the observed terminal strain contrast in terms of a screw dislocation dipole model.

Preferential Sputtering of Ni3Al Single Crystals Studied Using Atom-Probe Field-Ion Microscopy and XPS

1981 ◽  
Vol 39 ◽  
pp. 16-17
Author(s):  
M.P. Thomas ◽  
A.R. Waugh ◽  
M.J. Southon ◽  
Brian Ralph
Keyword(s):  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Depth Profiling ◽  
Analytical Techniques ◽  
Atom Probe ◽  
Probe Field ◽  
Preferential Sputtering ◽  
Argon Ion Bombardment ◽  
Argon Ion

It is well known that ion-induced sputtering from numerous multicomponent targets results in marked changes in surface composition (1). Preferential removal of one component results in surface enrichment in the less easily removed species. In this investigation, a time-of-flight atom-probe field-ion microscope A.P. together with X-ray photoelectron spectroscopy XPS have been used to monitor alterations in surface composition of Ni3Al single crystals under argon ion bombardment. The A.P. has been chosen for this investigation because of its ability using field evaporation to depth profile through a sputtered surface without the need for further ion sputtering. Incident ion energy and ion dose have been selected to reflect conditions widely used in surface analytical techniques for cleaning and depth-profiling of samples, typically 3keV and 1018 - 1020 ion m-2.

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