Stark levels, selection rules, and polarized cross sections of Yb:GdVO4 single crystal

Author(s):  
Yoichi Sato ◽  
Takunori Taira ◽  
Osamu Nakamura ◽  
Yasunori Furukawa
2021 ◽  
Vol 2086 (1) ◽  
pp. 012175
Author(s):  
A Volokitina ◽  
P Loiko ◽  
E Dunina ◽  
A Kornienko ◽  
J M Serres ◽  
...  

Abstract Polarization anisotropy of luminescent properties of europium (III) ions in low-symmetry C2 sites is studied using monoclinic (sp. gr. C2/c) tungstate crystal KY(WO4)2. The 5D0 → 7FJ (where J = 0…6) transitions are characterized for the principal light polarizations. Polarization selection rules for the magnetic dipole 5D0 → 7F1 transition are presented. The stimulated-emission cross-sections for Eu3+ ions relevant for laser operation are determined.


CrystEngComm ◽  
2009 ◽  
Vol 11 (9) ◽  
pp. 1863 ◽  
Author(s):  
Yan Zhou ◽  
Ya-Xi Huang ◽  
Yuanming Pan ◽  
Jin-Xiao Mi

2016 ◽  
Vol 61 (2) ◽  
pp. 1129-1134 ◽  
Author(s):  
J. Krawczyk

Abstract The microstructure of as-cast cored turbine blades roots, made of the single-crystal CMSX-4 nickel-based superalloy was investigated. Analysed blades were obtained by directional solidification technique in the industrial ALD Bridgman induction furnace. The investigations of the microstructure of blades roots were performed using SEM and X-ray techniques including diffraction topography with the use of Auleytner method. Characteristic shapes of dendrites with various arrangement were observed on the SEM images taken from the cross-sections, made transversely to the main blades axis. The differences in quality of the structure in particular areas of blades roots were revealed. Based on the results, the influence of cooling bores on blades root structure was analysed and the changes in the distribution and geometry of cooling bores were proposed.


1996 ◽  
Vol 52 (1) ◽  
pp. 140-144 ◽  
Author(s):  
H. van Koningsveld ◽  
J. C. Jansen ◽  
H. van Bekkum

The crystal structure of a high-loaded complex of H-ZSM-5 with eight molecules of p-dichlorobenzene per unit cell has been solved by single-crystal X-ray diffraction. The orthorhombic space group P212121 with a = 20.102 (6), b = 19.797 (9), c = 13.436 (3) Å and V = 5347 (3) Å3 has four Si23.92Al0.08O48.2C6H4Cl2 units per unit cell. Dx = 2.164 Mg m−3, λ(MoKα) = 0.71073 Å and μ(Mo Kα) = 0.876 mm−1. The final R(wR) = 0.046 (0.039), w = 1/σ 2(F), for 6090 observed reflections with I > 1.0σ(I) measured at 293 K. The straight channel parallel to [010] is slightly corrugated. The elliptical cross sections have limiting apertures of 6.0 × 4.9 Å (r oxygen = 1.35 Å). The sinusoidal channel parallel to [100] is elliptical with major and minor axes of 6.1 × 4.8 Å, respectively. One of the two independent p-dichlorobenzene molecule lies at the intersection of the straight and sinusoidal channels with its long molecular axis almost parallel to (100) and deviating ~8° from [010]. The second p-dichlorobenzene molecule is in the sinusoidal channel. Its long molecular axis deviates almost 7° from [100] and is practically parallel to (010). The structural aspects are in all details comparable to those in the high-loaded H-ZSM-5/p-xylene complex [van Koningsveld, Tuinstra, van Bekkum & Jansen (1989). Acta Cryst. B45, 423–431] , except for the main interaction forces between the p-dichlorobenzene molecules at the channel intersection.


2009 ◽  
Vol 24 (3) ◽  
pp. 844-852 ◽  
Author(s):  
M.J. Cordill ◽  
N.R. Moody ◽  
S.V. Prasad ◽  
J.R. Michael ◽  
W.W. Gerberich

In ductile metals, sliding contact induces plastic deformation resulting in subsurfaces, the mechanical properties of which are different from those of the bulk. This article describes a novel combination of nanomechanical test methods and analysis techniques to evaluate the mechanical behavior of the subsurfaces generated underneath a wear surface. In this methodology, nanoscratch techniques were first used to generate wear patterns as a function of load and number of cycles using a Hysitron TriboIndenter. Measurements were made on a (001) single crystal plane along two crystallographic directions, <001> and <011>. Nanoindentation was then used to measure mechanical properties in each wear pattern. The results on the (001) single crystal nickel plane showed that there was a strong increase in hardness with increasing applied load that was accompanied by a change in surface deformation. The amount of deformation underneath the wear patterns was examined from focused ion beam cross-sections of the wear patterns.


1974 ◽  
Vol 29 (6) ◽  
pp. 833-837 ◽  
Author(s):  
H. Drescher ◽  
E. R. Krefting ◽  
L. Reimer ◽  
H. Seidel

A theory is developed for calculating the orientation dependence of the backscattering coefficient of single crystal films. Three contributions are calculated separately; firstly the direct Lackscattering out of the Bloch wave field, secondly the backscattering of electrons scattered out of the wave field into angles smaller than 90° and thirdly the remaining fraction of electrons scattered into very small angles. The electron diffusion is considered by Monte-Carlo calculations. The results are approximated by simple analytical formulas for computation. The theory is compared with experiments on gold single crystal films on a mica substrate. For primary electron energies below 6 keV, a decrease of the orientation anisotropy of backscattering is observed with decreasing energy, whereas Si and Ge single crystals show a further increase. This decrease agrees with numerical calculations using cross sections for low energies.


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