scholarly journals Preparation of Samarium Doped Calcium Hydrogen Phosphate and Study of Its Density and Thermal and Dielectric Characteristics

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
K. K. Bamzai ◽  
Goldy Slathia ◽  
Bindu Raina ◽  
Rashmi Gupta ◽  
Seema Verma ◽  
...  

Samarium doped calcium hydrogen phosphate was synthesized as single crystal by room temperature solution growth technique, namely, silica gel technique. The kinetics of the growth parameters was studied with regard to variation of pH, dopant concentration, gel ageing, and upper reactant concentration. The optimum conditions for the growth of good quality single crystal were worked out. Single crystal X-ray diffraction analysis establishes that the crystal belongs to monoclinic system. The density observed by the flotation method is greater than the density of the reported pure calcium hydrogen phosphate thereby suggesting the incorporation of the dopant (Sm) ion into the lattice of host (CHP). Thermal analysis gave two sharp endothermic peaks which are due to partial dehydration and phase transition, respectively. Dielectric studies establish a shift in the Curie temperature from 355 to 370°C only at higher frequencies thereby suggesting the relaxational behavior of the material.

2009 ◽  
Vol 6 (3) ◽  
pp. 871-879 ◽  
Author(s):  
R. Kanagadurai ◽  
R. Durairajan ◽  
R. Sankar ◽  
G. Sivanesan ◽  
S. P. Elangovan ◽  
...  

Solubility, metastable zone width and induction period measurements have been performed on zinc sulphate heptahydrate (ZSHH). Interfacial tension values determined from induction period measurements have been used for the evaluation of the nucleation parameters such as radius of critical nucleus and the free energy of formation of critical nucleus. ZSHH crystallizes in the orthorhombic structure. Crystals of diamagnetic zinc sulphate heptahydrate have been grown by temperature lowering solution growth technique with the optimized growth parameters. The as-grown ZSHH crystals were characterized by the powder X-ray diffraction, UV-VIS absorption and transmittance, FT-IR absorption, TG-DTA, microhardness and etching studies.


Author(s):  
A. Ruby

L-Valine zinc acetate (LVZA) was synthesized and its solubility was estimated in the solvent of double distilled water. Single crystals of LVZA were grown by slow evaporation solution growth technique. The cell parameters were obtained by single crystal X-ray diffraction study. Functional groups of LVZA were identified by FTIR analysis. UV-vis-NIR spectral studies showed the optical nature of LVZA. Kurtz powder technique revealed the SHG efficiency of LVZA. Thermal properties of the grown LVZA crystal were studied from TGA/ DTA and DSC spectrum. Vickers’s mechanical hardness values were found for the grown crystal.


2020 ◽  
Vol 151 (9) ◽  
pp. 1317-1328
Author(s):  
Matthias Weil ◽  
Berthold Stöger

Abstract The caesium phosphates Cs3(H1.5PO4)2(H2O)2 and Cs3(H1.5PO4)2 were obtained from aqueous solutions, and Cs4P2O7(H2O)4 and CsPO3 from solid state reactions, respectively. Cs3(H1.5PO4)2, Cs4P2O7(H2O)4, and CsPO3 were fully structurally characterized for the first time on basis of single-crystal X-ray diffraction data recorded at − 173 °C. Monoclinic Cs3(H1.5PO4)2 (Z = 2, C2/m) represents a new structure type and comprises hydrogen phosphate groups involved in the formation of a strong non-symmetrical hydrogen bond (accompanied by a disordered H atom over a twofold rotation axis) and a very strong symmetric hydrogen bond (with the H atom situated on an inversion centre) with symmetry-related neighbouring anions. Triclinic Cs4P2O7(H2O)4 (Z = 2, P$$\bar{1}$$ 1 ¯ ) crystallizes also in a new structure type and is represented by a diphosphate group with a P–O–P bridging angle of 128.5°. Although H atoms of the water molecules were not modelled, O···O distances point to hydrogen bonds of medium strengths in the crystal structure. CsPO3 is monoclinic (Z = 4, P21/n) and belongs to the family of catena-polyphosphates (MPO3)n with a repetition period of 2. It is isotypic with the room-temperature modification of RbPO3. The crystal structure of Cs3(H1.5PO4)2(H2O)2 was re-evaluated on the basis of single-crystal X-ray diffraction data at − 173 °C, revealing that two adjacent hydrogen phosphate anions are connected by a very strong and non-symmetrical hydrogen bond, in contrast to the previously described symmetrical bonding situation derived from room temperature X-ray diffraction data. In the four title crystal structures, coordination numbers of the caesium cations range from 7 to 12. Graphic abstract


2014 ◽  
Vol 04 (02) ◽  
pp. 1450007 ◽  
Author(s):  
Shivani Suri ◽  
Vishal Singh ◽  
K. K. Bamzai

Neodymium-doped barium phosphate (NdBP) was prepared as single crystal by room temperature solution technique known as gel encapsulation technique. Single crystal X-ray diffraction shows that the crystal belongs to orthorhombic system. The flower type morphology was observed by scanning electron microscope (SEM) and the stoichiometric composition of the prepared crystal was observed by energy dispersive X-ray analysis (EDAX). The presence of functional group and other groups was studied by Fourier transform infrared spectroscopy (FTIR). The electrical properties of these materials like dielectric constant (ε′), dielectric loss (tanδ) and ac conductivity [ln(σac)] was studied at different temperatures ranging from 40°C to 420°C in the frequency range of 5 kHz to 1 MHz. The activation energy values decreases with increase in frequency suggesting that the conduction mechanism is because of hopping of charge carriers.


2009 ◽  
Vol 23 (09) ◽  
pp. 1221-1227
Author(s):  
K. SELVARAJU ◽  
K. KIRUBAVATHI ◽  
S. KUMARARAMAN

Single crystals of 2-Naphthalenol (2N), new organic nonlinear optical (NLO) material, have been grown by slow evaporation solution growth technique at room temperature. The crystal system has been confirmed from the single crystal X-ray diffraction analysis. The functional groups were identified using FTIR spectroscopy. UV-vis-NIR spectrum showed absence of absorption in the wavelength region 400–1400 nm. The second harmonic generation efficiency is two times higher than that of standard potassium dihydrogen phosphate (KDP).


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
M. Amudha ◽  
R. Rajkumar ◽  
V. Thayanithi ◽  
P. Praveen Kumar

A new organic charge transfer molecular complex salt of benzimidazolium salicylate (BSL) single crystals was grown by the slow evaporation solution growth technique using methanol as a solvent at room temperature. The grown crystals were characterised by single crystal X-ray diffraction (XRD) which confirms that the crystal belongs to monoclinic system with the centrosymmetric space group P21/c. The crystalline perfection of the grown crystal was analyzed by high resolution X-ray diffraction (HRXRD). The presence of various functional groups was identified by FTIR spectrum. UV-Vis spectral study reveals that the BSL crystal is optically transparent in the wavelength region 342 nm–1100 nm. Dielectric measurements of the crystal at various frequencies were also determined. The mechanical properties of the grown crystal were assessed using Vickers microhardness testing. Nonlinear optical property of the crystal was confirmed using Kurtz and Perry powder technique and the SHG efficiency of the BSL crystal is 0.7 times greater than that of the standard KDP crystal.


1980 ◽  
Vol 35 (10) ◽  
pp. 1203-1206 ◽  
Author(s):  
Johannes C. P. M. Lapidaire ◽  
Anthoni J. De Kok

Abstract The crystal and molecular structure of dodecamethyl bisimidotriphosphoramide mono-hydrate (TRIPA • H2O, C12H38N7O4P3) has been determined by single crystal X-ray diffraction techniques. The compound crystallises in the monoclinic system, space group P2i/n with a = 9.236(3), b = 14.016(4), c = 17.534(5) A, β = 97.32(4)°, Z = 4. The building units are dimers of TRIPA • H2O. These units are separated by normal van der Waals distances. The two molecules in the dimer are connected by four hydrogen bridges involving two water molecules. The nitrogen atoms display a nearly planar hybridisation.


2010 ◽  
Vol 638-642 ◽  
pp. 2227-2232 ◽  
Author(s):  
Alexander Epishin ◽  
Thomas Link ◽  
Udo Brückner

New experimental methods developed by the authors for characterisation of the structure of single-crystal nickel-base superalloys are presented: X-ray diffraction at defined areas of the dendritic structure, none destructive SEM investigation of ’-morphology changes for different creep stresses and times with one specimen, and high resolution SEM investigations of dislocations in the ’-interfaces. Application of these techniques allowed to obtain new results, e.g. about the mosaicity of dendritic subgrains, distribution of the ’-misfit within a single dendrite and kinetics of rafting during creep in the superalloy CMSX-4 in wide temperature and stress ranges.


Author(s):  
M. Akkurt ◽  
E. Sarıpınar ◽  
S. Öztürk ◽  
C. Yılmaz ◽  
H.-K. Fun

AbstractThe crystal structure of (4-methoxy-phenyl)-[4-(4-methoxy-phenyl)-1-(1-phenylethylideneamino)-2-thioxo-1,2-dihydro-pyrimidin-5-yl]-methanone, has beeen determined by single-crystal X-ray diffraction at 183(2) K. The compound crystallizes in the monoclinic system, space group


2009 ◽  
Vol 23 (25) ◽  
pp. 3035-3043 ◽  
Author(s):  
G. PASUPATHI ◽  
P. PHILOMINATHAN

Single crystals of tris (Thiourea) magnesium sulphate (MTS) were grown from aqueous solution by low temperature solution growth technique. The grown crystals have been characterized by X-ray diffraction to confirm the formation of the crystalline phases. The presence of functional groups was identified by Fourier transform infrared spectroscopy. The optical transmission spectrum showed that a lower cut-off wavelength of MTS crystal is below 300 nm and it has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. The thermal stabilities were studied by differential thermal analysis (DTA) and thermo gravimetric analysis (TGA). Nonlinear optical characteristics of MTS were studied using Q-switched Nd:YAG laser (λ=1064 nm ). The micro-hardness studies reveal the mechanical properties of the grown crystals.


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