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41.
Third-order nonlinear optical susceptibility, χ(3) of symmetrically octa-substituted metal-free phthalocyanine thin films measured by the third-harmonic generation technique are reported. The metal-free phthalocyanine has been found to show a χ(3) (−3ω; ω,ω, ω) value as large as 7.73×10−12 esu at 1.80 μm. The figure of merit, χ(3)/α, was estimated to be 4.17×1017 esu cm at 1.05 μm and 6.97×1016 esu cm at 1.65 μm. Both linear and third-order optical properties of liquid-crystalline metal-free phthalocyanines are discussed 相似文献
42.
The Vickers indentation hardness of Hg1−xCdxTe has been measured as a function of composition x using monocrystalline samples of Bridgman and THM crystals and polycrystalline starting material at room temperature. The microhardness varied between 220 MPa (x=0) and 440 MPa (x=1), showing a maximum of 850 MPa at x ∼ 0.75, and was different between monocrystalline and polycrystalline samples. The “hardening rate” dH/dx is strongly dependent on the composition range and is discussed in context with solid solution hardening due to elastic interactions of solute atoms with gliding dislocations and ordering effects. 相似文献
43.
L. Hock F. H. Müller H. Thiele Flügge H. Erbring F. V. A. Engel Sippel E. Gruner R. Jäger 《Colloid and polymer science》1951,122(3):179-182
Ohne Zusammenfassung 相似文献
44.
Exciton‐Vibrational Couplings in Homo‐ and Heterodimer Stacks of Perylene Bisimide Dyes within Cyclophanes: Studies on Absorption Properties and Theoretical Analysis
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David Bialas Christoph Brüning Dr. Felix Schlosser Dr. Benjamin Fimmel Johannes Thein Prof. Dr. Volker Engel Prof. Dr. Frank Würthner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):15011-15018
The optical properties of a series of three cyclophanes comprising either identical or different perylene bisimide (PBI) chromophores were studied by UV/Vis absorption spectroscopy and their distinctive spectral features were analyzed. All the investigated cyclophanes show significantly different absorption features with respect to the corresponding constituent PBI monomers indicating strong coupling interactions between the PBI units within the cyclophanes. DFT calculations suggest a π‐stacked arrangement of the PBI units at close van der Waals distance in the cyclophanes with rotational displacement. Simulations of the absorption spectra based on time‐dependent quantum mechanics properly reproduced the experimental spectra, revealing exciton‐vibrational coupling between the chromophores both in homo‐ and heterodimer stacks. The PBI cyclophane comprising two different PBI chromophores represents the first example of a PBI heterodimer stack for which the exciton coupling has been investigated. The quantum dynamics analysis reveals that exciton coupling in heteroaggregates is indeed of similar strength as for homoaggregates. 相似文献
45.
First full-relativistic density functional calculations with the extension of the spin-polarization functional for the relativistic density functional theory in their collinear and noncollinear form are presented here for the molecular system Pt2. The agreement with experiment is very good. 相似文献
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Polymorphic transitions of HgSexTe(1 ? x) induced by pressure were investigated for 0 <- x <- 1. The transitions were followed by both volume and resistivity measurements on samples of different alloy compositions and of different textures. The transition pressure seems to be a linear function of the alloy composition. 相似文献
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The reconstructed Au(100) surface has been investigated using He-diffraction techniques. The topmost layer is found to have a dominant (1 × 5) periodicity, whereby the corrugation appears one-dimensional in the direction of the longer unit cell. The complex LEED patterns observed for this surface must be due to secondary structural features such as minor atomic displacements in the topmost or lower layers. Several reconstruction models were considered and surface electron density calculations were performed to enable a comparison with the corrugation functions deduced from the He-diffraction data. 相似文献