scholarly journals Growth and study of barium oxalate single crystals in agar gel

2006 ◽  
Vol 29 (5) ◽  
pp. 421-425 ◽  
Author(s):  
P. V. Dalal ◽  
K. B. Saraf
Keyword(s):  
Single Crystals ◽  
Agar Gel ◽  
Barium Oxalate

scholarly journals Thermal Conductivity of Gel-Grown Barium Oxalate at 326 and 335 K

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Paresh Vasantlal Dalal
Keyword(s):  
Thermal Conductivity ◽  
Ambient Temperature ◽  
Single Crystals ◽  
Free Path ◽  
Grown Crystal ◽  
Mean Free Path ◽  
Monoclinic Structure ◽  
Agar Gel ◽  
Gel Method ◽  
Barium Oxalate

Single crystals of barium oxalate have been grown by gel method using agar-agar gel as media of growth at ambient temperature. The grown crystal crystallizes under monoclinic structure. Thermal conductivity of gel-grown barium oxalate crystals as a function of temperature has been studied at 326 and 335 K by using divided bar method. The thermal conductivity of barium oxalate crystal at 326 K was found 3.685 W m−1 K−1 and 3.133 W m−1 K−1 at 335 K. The reduction of thermal conductivity with the rise in temperature may be due to reduction in mean free path of phonons in the solid.

Growth aspects of barium oxalate monohydrate single crystals in gel medium

2008 ◽  
Vol 43 (12) ◽  
pp. 1307-1313 ◽  
Author(s):  
A. Moses Ezhil Raj ◽  
D. Deva Jayanthi ◽  
V. Bena Jothy ◽  
M. Jayachandran ◽  
C. Sanjeeviraja
Keyword(s):  
Single Crystals ◽  
Barium Oxalate

Growth of barium oxalate crystals in agar-agar gel and their characterization

2009 ◽  
Vol 44 (1) ◽  
pp. 36-42 ◽  
Author(s):  
P. V. Dalal ◽  
K. B. Saraf ◽  
S. Shah
Keyword(s):  
Agar Gel ◽  
Barium Oxalate ◽  
Oxalate Crystals

scholarly journals Pyro and Kinetic Studies of Barium Oxalate Crystals Grown in Agar Gel

2012 ◽  
Vol 02 (04) ◽  
pp. 156-160 ◽  
Author(s):  
Paresh V. Dalal ◽  
Kishor B. Saraf ◽  
Navinchandra G. Shimpi ◽  
Navneet R. Shah
Keyword(s):  
Kinetic Studies ◽  
Agar Gel ◽  
Barium Oxalate ◽  
Oxalate Crystals

scholarly journals Synthesis, Crystal Structure, and Thermal Properties of CaSO4·2H2O Single Crystals

2015 ◽  
Vol 7 (2) ◽  
pp. 12 ◽  
Author(s):  
Takanori Fukami ◽  
Shuta Tahara ◽  
Keiko Nakasone ◽  
Chitoshi Yasuda
Keyword(s):  
Crystal Structure ◽  
Weight Loss ◽  
Single Crystals ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Agar Gel ◽  
X Ray ◽  
Calcium Sulfate Dihydrate ◽  
White Substance

Single crystals were grown at room temperature from the precursors CaCO3 and NH2SO3H by a gel method using agar-agar gel as the medium of growth. Differential scanning calorimetry, thermogravimetric–differential thermal analysis, and X-ray diffraction measurements were performed on the single crystals. The crystal structure of the grown crystals was confirmed to be very similar to that of calcium sulfate dihydrate (CaSO4·2H2O, gypsum). The temperature at which dehydration and evaporation of intercalated water molecules in the single crystal occurred was found to be 375.9 K, which was very close to that in CaSO4·2H2O. From all these results, we identified the grown single crystals as CaSO4·2H2O. The weight loss owing to the thermal decomposition of anhydrous CaSO4 formed by the dehydration of the single gypsum crystals was found to occur at ~1530 K. This weight loss was probably caused by the evolution of SO3 gas by sublimation, and the chalky white substance left in the open vessel after decomposition was calcium oxide (CaO).

scholarly journals Morphological and FTIR Studies of Barium Oxalate Single Crystals

2017 ◽  
Vol 25 (2) ◽  
pp. 195-207
Author(s):  
M. R. Shedam ◽  
Rakesh M. Shedam ◽  
Shridhar N. Mathad
Keyword(s):  
Single Crystals ◽  
Feed Solution ◽  
Silica Gels ◽  
Effect Of Temperature ◽  
Nucleation Density ◽  
Gel Growth ◽  
Ftir Studies ◽  
Barium Oxalate ◽  
Oxalate Crystals ◽  
Higher Temperature

Abstract The conditions for the gel growth of barium oxalate single crystals in silica gels were studied in this paper. We describe the growth mechanism, effect concentration of feed solution, interchanging of the reactants, the effect of temperature and detailed study of microstructures of barium oxalate single crystals. At higher concentration of feed solution dense fibers were observed. With interchanged feed solution precipitate and spherulites have been obtained. The effect of temperature on growth barium oxalate crystals showed that there was a decrease in nucleation density at higher temperature. The crystals growth were observed under the electron microscope which revealed that the crystal have needle and spherulites structures. We also report the FTIR studies of barium oxalate crystals.

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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