scholarly journals Growth and Characterization of Epsomite Single Crystals Doped with KCl from low Temperature Aqueous Solutions

1970 ◽  
Vol 33 (1) ◽  
pp. 47-54 ◽  
Author(s):  
S Ferdous ◽  
J Podder
Keyword(s):  
Aqueous Solutions ◽  
Single Crystals ◽  
Optical Quality ◽  
Dielectric Studies ◽  
Slow Cooling ◽  
Large Size ◽  
Isothermal Evaporation ◽  
Academy Of Sciences

Highly transparent and well faceted large size epsomite single crystals have been grown in pure form and doped with KCl from aqueous solutions by slow cooling and isothermal evaporation method. The optical quality of the epsomite improves on doping by KCl. Mass growth rates were found to increase with doping of lower concentrations of KCl and then decreases with the higher concentration of KCl. KCl doped epsomite crystal reveals that structures are slightly distorted due to adsorption of Cl- ion into the crystal lattice. DC conductivity along the growth axis for all of the grown crystals increases with temperature in the range of 25 to 70ºC and also increases with the KCl concentration. Dielectric constant is found to be almost independent of frequency up to range of 106Hz. The dielectric studies show the suitability of these grown crystals for optoelectronic applications. DOI: 10.3329/jbas.v33i1.2949 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 1, 47-54, 2009

Crystal structure, thermal expansion and elastic properties of triclinic betaine hydrogen dihydrogen triiodate, ((CH3)3NCH2COOH)H2(IO3)3

1996 ◽  
Vol 211 (12) ◽  
Author(s):  
S. Haussühl ◽  
J. Schreuer
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Aqueous Solutions ◽  
Single Crystals ◽  
Elastic Properties ◽  
Structure Analysis ◽  
Optical Quality ◽  
Space Group ◽  
X Ray

AbstractLarge single crystals of optical quality of betaine hydrogen dihydrogen iodate have been grown from aqueous solutions. An X-ray structure analysis yields space group

Crystal structure, thermal expansion and dielectric properties of monoclinic ethylenediammonium bis(hydrogensuccinate), H3N(CH2)2NH3(HC4H4O4)2

1994 ◽  
Vol 209 (1) ◽  
Author(s):  
J. Schreuer ◽  
T. Münch
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Dielectric Properties ◽  
Aqueous Solutions ◽  
Single Crystals ◽  
Structure Analysis ◽  
Optical Quality ◽  
Space Group ◽  
X Ray

AbstractLarge single crystals of optical quality of monoclinic ethylenediammonium bis(hydrogensuccinate) were grown from aqueous solutions. An X-ray structure analysis yielded space group

Crystal structure, thermal expansion and elastic properties of triclinic betaine hydrogen ammonium sulfate, ((CH3)3NCH2COOH)NH4SO4

1996 ◽  
Vol 211 (2) ◽  
Author(s):  
S. Haussühl ◽  
J. Schreuer
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Aqueous Solutions ◽  
Single Crystals ◽  
Ammonium Sulfate ◽  
Elastic Properties ◽  
Structure Analysis ◽  
Optical Quality ◽  
X Ray

AbstractLarge single crystals of optical quality of betaine hydrogen ammonium sulfate have been grown from aqueous solutions. An X-ray structure analysis yielded space group

Elastic properties of citric acid, citric acid hydrate, trilithium citrate tetrahydrate, trisodium citrate pentahydrate, and tripotassium citrate hydrate

1999 ◽  
Vol 214 (2) ◽  
Author(s):  
S. Haussühl ◽  
Wang Jiyang
Keyword(s):  
Citric Acid ◽  
Aqueous Solutions ◽  
Single Crystals ◽  
Elastic Constants ◽  
Trisodium Citrate ◽  
Optical Quality ◽  
Citric Acid Monohydrate ◽  
Standard Methods ◽  
Acid Hydrate

AbstractSingle crystals of optical quality of citric acid (monoclinic), citric acid monohydrate (orthorhombic), trilithium citrate tetrahydrate (monoclinic), trisodium citrate pentahydrate (orthorhombic) and tripotassium citrate monohydrate (monoclinic) have been grown from aqueous solutions by standard methods. Elastic constants

Characterization of Natural and Synthesized FeTiO3 Crystals With RBS/PIXE/XRD

1997 ◽  
Vol 07 (03n04) ◽  
pp. 265-275
Author(s):  
R. Q. Zhang ◽  
S. Yamamoto ◽  
Z. N. Dai ◽  
K. Narumi ◽  
A. Miyashita ◽  
...  
Keyword(s):  
Single Crystals ◽  
Ion Beam ◽  
Pressure Control ◽  
Floating Zone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Beam Analysis ◽  
Ppm Level

Natural FeTiO 3 (illuminate) and synthesized FeTiO 3, single crystals were characterized by Rutherford backscattering spectroscopy combined with channeling technique and particle-induced x-ray emission (RBS-C and PIXE). The results obtained by the ion beam analysis were supplemented by the x-ray diffraction analysis to identify the crystallographic phase. Oriented single crystals of synthesized FeTiO 3 were grown under the pressure control of CO 2 and H 2 mixture gas using a single-crystal floating zone technique. The crystal quality of synthesized FeTiO 3 single crystals could be improved by the thermal treatment but the exact pressure control is needed to avoid the precipitation of Fe 2 O 3 even during the annealing procedure. Natural FeTiO 3 contains several kinds of impurities such as Mn , Mg , Na and Si . The synthesized samples contain Al , Si and Na which are around 100 ppm level as impurities. The PBS-C results of the natural sample imply that Mn impurities occupy the Fe sublattice in FeTiO 3 or in mixed phase between ilmenite and hematite.

Growth and characterization of large-size bismuth germanate single crystals by low thermal gradient Czochralski method

1999 ◽  
Vol 197 (4) ◽  
pp. 865-873 ◽  
Author(s):  
R.V Anantha Murthy ◽  
M Ravikumar ◽  
A Choubey ◽  
Krishan Lal ◽  
Lyudmila Kharachenko ◽  
...  
Keyword(s):  
Single Crystals ◽  
Thermal Gradient ◽  
Czochralski Method ◽  
Bismuth Germanate ◽  
Large Size

Photoluminescence Characterization of SiGe/Si Quantum-Well Wire Structures

1995 ◽  
Vol 379 ◽  
Author(s):  
S. Nilsson ◽  
H. P. Zeindl ◽  
A. Wolff ◽  
K. Pressel
Keyword(s):  
Quantum Well ◽  
Room Temperature ◽  
Molecular Beam ◽  
Optical Quality ◽  
Photoluminescence Spectra ◽  
Single Quantum Well ◽  
Quantum Well Wire ◽  
Carbon Interstitial

ABSTRACTLow-temperature photoluminescence measurements were performed in order to probe the optical quality of SiGe/Si quantum-well wire structures fabricated by electron-beam lithography and subsequent reactive ion etching, having the patterned polymethylmethacrylate resist as an etch mask. In addition, one set of quantum-well wire structures was post-treated by means of annealing in a hydrogen environment. Our results show that even for the smallest wires of about 100nm in width, the wires exhibit phonon-resolved photoluminescence spectra, similar to that from the molecular beam eptitaxially grown SiGe single quantum well which was used as starting material for the patterning process. After the patterning process a new sharp peak appears in the photoluminescence spectra at 0.97eV in photon energy. Our investigation suggests that this feature is introduced by damage during the patterning process and most probably identical to the G-line, which previously was identified as originating from the dicarbon centre (substitutional carbon-interstitial carbon) in Si. This centre is known to be a very common endproduct of irradiating Si near room temperature which is the case at our patterning process.

Cyclic polyamines as templates for novel complex topologies in uranyl sulfates and selenates

2018 ◽  
Vol 233 (3-4) ◽  
pp. 233-245 ◽  
Author(s):  
Vladislav V. Gurzhiy ◽  
Olga S. Tyumentseva ◽  
Sergey V. Krivovichev ◽  
Ivan G. Tananaev
Keyword(s):  
Crystal Structure ◽  
Aqueous Solutions ◽  
Single Crystals ◽  
Complexity Measures ◽  
Topological Approach ◽  
Isothermal Evaporation ◽  
Novel Complex ◽  
Chemical Conditions

AbstractSingle crystals of two novel uranyl sulfates and two novel uranyl selenates with protonated cyclen and 3-aminotropane molecules, ((C8H24N4)[(UO2)3(SO4)5](H2O)3(I), (C8H24N4)(H5O2)(H3O)[(UO2)4(SeO4)7(H2O)](H2O)6.6(II), (C8H18N2)(H5O2)(H3O)[(UO2)3(SO4)5(H2O)](H2O)0.5(III), and (C8H18N2)(H5O2)(H3O)[(UO2)3(SeO4)5(H2O)](H2O)2(IV) have been prepared by isothermal evaporation from aqueous solutions and structurally characterized. Uranyl-containing 2D units have been investigated using topological approach and information-based complexity measures demonstrating that complex topologies form more rare than their simplest counterparts, which is a response of the crystal structure to changes of chemical conditions within the system.

Detection, identification and mapping of cyanobacteria — Using remote sensing to measure the optical quality of turbid inland waters

1994 ◽  
Vol 45 (5) ◽  
pp. 801 ◽  
Author(s):  
DLB Jupp ◽  
JTO Kirk ◽  
GP Harris
Keyword(s):  
Remote Sensing ◽  
Algal Species ◽  
Optical Quality ◽  
High Spectral Resolution ◽  
Turbid Waters ◽  
Eastern Australia ◽  
Processing Techniques ◽  
Compact Airborne Spectrographic Imager

The advantages of airborne scanning for the detection, identification and mapping of algal species, cyanobacteria and associated water parameters (such as turbidity) can be realized if current research outcomes are developed into operational methods based on images with high spectral resolution. Evidence for this has become available through data obtained recently in Australia from the Compact Airborne Spectrographic Imager. This paper shows how pigments associated with cyanobacteria are detectable, even in the very turbid waters typical of eastern Australia. It demonstrates how, if the waterbodies and their constituents can be characterized by a programme of field and laboratory measurement, current processing techniques and models allow the concentrations of different constituents (algae and particles) in the photic zone to be estimated and mapped. The challenge for operational remote sensing of optical water quality in Australia (and throughout the world) is seen to have two components. One is to provide an effective characterization of the target inland and adjacent coastal waters and the other is to streamline the data analysis to provide maps of water properties in the time and cost frameworks required for operational use.

Growth and Characterization of Single Crystal Epitaxial CoGa on MBE Grown III-V Semiconductors

1988 ◽  
Vol 144 ◽  
Author(s):  
K. C. Garrison ◽  
C. J. Palmstrøm ◽  
R. A. Bartynski
Keyword(s):  
Substrate Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Structural Quality ◽  
High Quality ◽  
Auger Analysis ◽  
Post Deposition

ABSTRACTWe have demonstrated growth of high quality single crystal CoGa films on Ga1−xAlxAs. These films were fabricated in-situ by codeposition of Co and Ga on MBE grown Ga1−xAlxAs(100) surfaces. The elemental composition of the films was determined using Rutherford Backscattering (RBS) and in-situ Auger analysis. The structural quality of the films' surfaces was studied using RHEED (during deposition) and LEED (post deposition). RBS channeling was used to determine the bulk crystalline quality of these films.For ∼500 Å CoGa films grown at ∼450°C substrate temperature, channeling data showed good quality epitaxial single crystals [χmin ∼7%] with minimal dechanneling at the interface.

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