Organic Crystals, Germanates, Semiconductors

1980 ◽  
Author(s):  
L. N. Demianets ◽  
G. A. Emelchenko ◽  
J. Hesse ◽  
N. Karl ◽  
A. N. Lobachev ◽  
...  
Keyword(s):  
Organic Crystals

Interpretation of irradiation-induced changes in electron diffractograms and images of extinction contours at low temperatures

1984 ◽  
Vol 42 ◽  
pp. 268-269
Author(s):  
E. Knapek ◽  
H. Formanek ◽  
G. Lefranc ◽  
I. Dietrich
Keyword(s):  
Low Temperatures ◽  
Carbon Films ◽  
Organic Crystals ◽  
Wide Spread ◽  
Lens System ◽  
Preparation Conditions ◽  
Thin Carbon ◽  
Electron Diffractograms ◽  
Diffraction Patterns ◽  
Induced Changes

A few years ago results on cryoprotection of L-valine were reported, where the values of the critical fluence De i.e, the electron exposure which decreases the intensity of the diffraction reflections by a factor e, amounted to the order of 2000 + 1000 e/nm2. In the meantime a discrepancy arose, since several groups published De values between 100 e/nm2 and 1200 e/nm2 /1 - 4/. This disagreement and particularly the wide spread of the results induced us to investigate more thoroughly the behaviour of organic crystals at very low temperatures during electron irradiation.For this purpose large L-valine crystals with homogenuous thickness were deposited on holey carbon films, thin carbon films or Au-coated holey carbon films. These specimens were cooled down to nearly liquid helium temperature in an electron microscope with a superconducting lens system and irradiated with 200 keU-electrons. The progress of radiation damage under different preparation conditions has been observed with series of electron diffraction patterns and direct images of extinction contours.

NONLINEAR CONDUCTIVITY IN QUASI-ONE-DIMENSIONAL ORGANIC CRYSTALS

1981 ◽  
Vol 42 (C7) ◽  
pp. C7-315-C7-322 ◽  
Author(s):  
E. M. Conwell ◽  
N. C. Banik
Keyword(s):  
Organic Crystals ◽  
Nonlinear Conductivity ◽  
One Dimensional

Shining Light on Growth-Dependent Surface Chemistry of Organic Crystals: A Polarized Raman Spectroscopic and Computational Study of Aspirin

2019 ◽  
Vol 19 (2) ◽  
pp. 1288-1298 ◽  
Author(s):  
Anuradha R. Pallipurath ◽  
Jonathan M. Skelton ◽  
Andrea Erxleben ◽  
Patrick McArdle
Keyword(s):  
Surface Chemistry ◽  
Computational Study ◽  
Organic Crystals ◽  
Raman Spectroscopic ◽  
Polarized Raman

Organic Crystals in the Tracheids of Torreya Yunnanensis

IAWA Journal ◽  
1996 ◽  
Vol 17 (4) ◽  
pp. 393-403 ◽  
Author(s):  
Yuki Kondo ◽  
Tomoyuki Fujii ◽  
Yoshioki Hayashi ◽  
Atsushi Kato
Keyword(s):  
Phase Contrast ◽  
Growth Ring ◽  
Uv Spectra ◽  
Resonance Spectroscopy ◽  
Organic Crystals ◽  
X Ray Diffraction ◽  
Cinnamic Aldehyde ◽  
X Ray ◽  
Polarised Light ◽  
Contrast Microscopy

Organic crystals were found in tracheid lumina of some samples of Torreya yunnanensis Chen ' L. K. Fu imported from Yunnan, China. Tracheids with crystals were found in short to long tangential bands along the growth ring boundaries. Because the crystals were rapidly dissolved with ethanol and xylene, cross and tangential sections were mounted in de-ionized water without staining and observed by biological, polarised light, and phase-contrast microscopy. The crystals were sublimated under vacuum during routine sample preparation for conventional SEM and only the peripheral parts remained. With the aid of low vacuum-SEM and modified cryo-SEM procedure, the shape of the crystals was revealed. Some were styloid and large enough to fill tracheid lumina, while others were stacked appearing as slates filling tracheid lumina. X-ray diffraction applied to sections and isolated crystals showed that they were single crystals and orientated along the cell wall. UV spectra on isolated crystals and methanol dissolution of crystals suggested that they were composed of phenolic compounds. Crystals that were recrystallized from methanol were analysed by 1H and l3C nuclear magnetic resonance spectroscopy. These two techniques revealed that the major and minor components were o-methoxy cinnamic acid and o-methoxy cinnamic aldehyde.

Crystal Growth, Spectral, Thermal and Optical Properties of Phthalic Anhydride (PA) Single Crystal

2012 ◽  
Vol 584 ◽  
pp. 136-140 ◽  
Author(s):  
S. Janarthanan ◽  
Y.C. Rajan ◽  
R. Sugaraj Samuel ◽  
S. Pandi
Keyword(s):  
Spectral Analysis ◽  
Single Crystal ◽  
Phthalic Anhydride ◽  
Second Harmonic ◽  
Organic Crystals ◽  
X Ray Diffraction ◽  
Fundamental Wavelength ◽  
Ft Ir ◽  
Raman Spectral ◽  
Raman Spectral Analysis

ABSTRACT Organic single crystal of Phthalic Anhydride (PA) was successfully grown by slow evaporation method. The structure of the grown crystal was confirmed by X-ray diffraction analysis. FT-IR, and FT-Raman spectral analysis of the crystalline samples reveal that the crystalline sample consists of all functional groups. The placement of protons was identified from H1-NMR spectral analysis. UV-Visible and photoluminescence spectral analyses were carried out for the grown crystals. The thermal behavior was studied with TGA-DTA analyses. The existence of second harmonic generation (SHG) signal was observed using Nd:YAG laser with a fundamental wavelength of 1064 nm. Keywords: Organic crystals, NLO crystals

Detection and determination of spatial distribution of the electroluminescence in thin organic crystals

1978 ◽  
Vol 17 (4) ◽  
pp. 467-470 ◽  
Author(s):  
Jan Kalinowski ◽  
Jan Godlewski ◽  
Jan Gliński
Keyword(s):  
Spatial Distribution ◽  
Organic Crystals

Formation of metal-lustrous organic crystals from 2-aryl-1-(4-methoxyphenyl)-5-(5-tricyanoethenyl-2-thienyl)pyrroles

Tetrahedron ◽  
2006 ◽  
Vol 62 (11) ◽  
pp. 2484-2491 ◽  
Author(s):  
Katsuyuki Ogura ◽  
Kenji Ooshima ◽  
Motohiro Akazome ◽  
Shoji Matsumoto
Keyword(s):  
Organic Crystals

Salient nonlinear optical properties of novel organic crystals comprising π‐conjugated ketones

1995 ◽  
Vol 66 (23) ◽  
pp. 3102-3104 ◽  
Author(s):  
Jun Kawamata ◽  
Kuon Inoue ◽  
Tamotsu Inabe
Keyword(s):  
Optical Properties ◽  
Nonlinear Optical ◽  
Nonlinear Optical Properties ◽  
Organic Crystals
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