Effect of trytophan as dopant on potassium acid phthalate single crystals

2019 ◽  
Author(s):  
Chem Int

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

2012 ◽  
Vol 584 ◽  
pp. 65-69
Author(s):  
P.S. Latha Mageshwari ◽  
R. Priya ◽  
S. Krishnan ◽  
V. Joseph ◽  
S. Jerome Das

Excellent and optically transparent good quality single crystals of cadmium chloride doped with lithium sulphate monohydrate (LS) were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X-ray diffraction analysis confirmed the changes in the lattice parameters of the cadmium chloride lithium sulphate (CCLS). The functional groups present in the CCLS crystals were determined qualitatively by using Fourier transform infrared (FTIR) spectroscopy. Optical absorption studies revealed that doped crystals acquire very low absorption in the entire visible region. Dielectric measurements show that the dielectric constant and dielectric loss of doped crystals decreases with increase of frequency.


2019 ◽  
Vol 1 (1) ◽  
pp. 42-45
Author(s):  
Tamiloli Devendhiran ◽  
Keerthika Kumarasamy ◽  
Mei–Ching Lin

Single crystals of 2-Aminothiazole 3,5-Dinitrobenzoic acid has been synthesized and good quality optical crystals were grown by slow evaporation technique at room temperature. The crystallinity nature of the grown crystal was confirmed from X-ray diffraction technique. An optical transmittance study was also carried out by UV – Vis spectra. FTIR spectra confirm the presence of functional groups in the grown crystal. The dielectric measurements were carried out in the range of 50Hz to 2MHz. The dielectric constant was seen to increase exponentially at lower frequencies. The microhardness studies were carried out using Vickers hardness indenter. Photoluminescence study shows that maximum emission occurs at 435nm.


2020 ◽  
Vol 38 (2) ◽  
pp. 214-218
Author(s):  
K. Mohanraj ◽  
D. Balasubramanian ◽  
N. Jhansi

AbstractNovel nonlinear optical semi-organic, potassium phthalate di lithium borate (KPDLiB) single crystals were successfully grown by the slow solvent evaporation technique. Good crystalline nature and an orthorhombic structure were confirmed by powder X-ray diffraction and single crystal X-ray diffraction studies. The functional groups of KPDLiB were identified using FT-IR spectrum recorded in the range of 4000 cm−1 to 450 cm−1. UV-Vis spectrum showed transmitting ability of the crystals in the entire visible region. The photoluminescence spectrum exhibited good fluorescence emission in a visible region at 384 nm, 416 nm and 578 nm. The second harmonic generation efficiency of the grown crystal was evaluated from Kurtz powder technique.


2004 ◽  
Vol 11 (01) ◽  
pp. 83-86 ◽  
Author(s):  
S. ABOUELHASSAN ◽  
F. SALMAN ◽  
M. ELMANSY ◽  
E. SHEHA

Single crystals of KHCO 3 were grown by the slow evaporation technique of an aqueous solution. Characterization of the sample was done using different techniques such as X-ray diffraction, infrared spectra (IR) and the differential scanning calorimeter (DSC) technique. The analysis of the X-ray diffraction pattern indicated that the sample was a single crystal. The results obtained by IR and DSC indicated the presence of phase transition. From the analysis of DSC, the activation energy of transition was carried out by two methods (Kissinger and Ozawa).


2021 ◽  
Vol 54 (5) ◽  
pp. 1317-1326
Author(s):  
Arsen Petrenko ◽  
Nataliya Novikova ◽  
Alexander Blagov ◽  
Anton Kulikov ◽  
Yury Pisarevskii ◽  
...  

The anisotropy of deformations in potassium acid phthalate crystals arising under the action of an external electric field up to 1 kV mm−1 applied along the [001] polar axis was studied using X-ray diffraction methods at room temperature. Electrical conductivity was measured and rocking curves for reflections 400, 070 and 004 were obtained by time-resolved X-ray diffractometry in Laue and Bragg geometries. Two saturation processes were observed from the time dependences of the electrical conductivity. A shift in the diffraction peaks and a change in their intensity were found, which indicated a deformation of the crystal structure. Rapid piezoelectric deformation and reversible relaxation-like deformation, kinetically similar to the electrical conductivity of a crystal, were revealed. The deformation depended on the polarity and strength of the applied field. The deformation was more noticeable in the [100] direction and was practically absent in the [001] direction of the applied field. X-ray diffraction analysis revealed a disordered arrangement of potassium atoms, i.e. additional positions and vacancies. The heights of potential barriers between the positions of K+ ions and the paths of their possible migration in the crystal structure of potassium acid phthalate were determined. The data obtained by time-resolved X-ray diffractometry and X-ray structure analysis, along with additional electrophysical measurements, allow the conclusion that the migration of charge carriers (potassium cations) leads to lateral deformation of the crystal structure of potassium phthalate in an external electric field.


2011 ◽  
Vol 306-307 ◽  
pp. 1722-1727 ◽  
Author(s):  
Man Mei ◽  
Li Li Cao ◽  
Yan He ◽  
Ru Ru Zhang ◽  
Fei Yun Guo ◽  
...  

The calcium terbium aluminate (CaTbAlO4) single crystal was grown by Czochralski method successfully for the first time.The structure of the crystal was determined by X-ray diffraction analysis.The transmission spectrum of the crystal was measured at room temperature at the wavelength of 400-1500nm.The specific Faraday rotation of the single crystal was surveyed at room temperature at the wavelength 532nm, 633nm, and 1064nm respectively.The Verdet constants of the CaTbAlO4 crystal are calculated and the results show that the Verdet constants of CaTbAlO4 are around 110% higher than that of TGG in the visible and near-infrared spectral region.Therefore,crystal CaTbAlO4 can be promising material for the fabrication of magneto-optical devices in the visible region.


2004 ◽  
Vol 82 (2) ◽  
pp. 301-305 ◽  
Author(s):  
Kenneth CW Chong ◽  
Brian O Patrick ◽  
John R Scheffer

When crystals of 9-tricyclo[4.4.1.0]undecalyl-4-(carbomethoxy)phenyl ketone (1) were allowed to stand in the dark for extended periods of time at room temperature, the compound underwent a thermal reaction — the enolene rearrangement — to afford enol 2. The crystals remained transparent and appeared unchanged in shape as the reaction proceeded. X-ray diffraction data were collected on single crystals containing 17%, 25%, 66%, and 100% of the enol. The crystal structure of a simple enol was obtained via this novel single-crystal-to-single-crystal enolene rearrangement.Key words: single crystal, thermal, rearrangement, enol, enolene.


2018 ◽  
Vol 15 (2) ◽  
pp. 151-158 ◽  
Author(s):  
K.G. Anupriya ◽  
P. Hemalatha

Single crystals of Sulphamic Acid doped with Zinc Sulphate and Manganese Sulphate were grown at room temperature using slow evaporation technique. Structural analysis of the grown crystals was done using single crystal X Ray Diffraction and powder X Ray Diffraction studies. Various functional groups seen in the grown crystals are determined using FTIR spectroscopic analysis. The cut-off wavelength of ZnSO4 and MnSO4 doped Sulphamic acid were evaluated by UV-Vis-NIR spectral studies. Thermal behaviour of the grown crystals was identified from Thermogravimetric Analysis (TGA) and Differential Thermogravimetric Analysis (DTA). The mechanical strength and Second harmonic generation of the grown crystals was identified by Vicker’s Microhardness Test and Kurtz powder technique respectively.


Author(s):  
S. Fujishiro ◽  
J. W. Edington

Compression tests were performed on titanium single crystals at room temperature and at −196°C, and the twinning mode was investigated using metallographic, electron microscopy and X-ray diffraction studies. Four crystallographic orientations, each different with respect to the compression axis, were selected in order to make the prospective twinning system planes, , , and , subject to a maximum resolved shear stress, i.e., Schmid factor = 0. 5. type twins were the most frequently observed in all the crystals tested and type twins were the second most frequent.


2014 ◽  
Vol 925 ◽  
pp. 164-168 ◽  
Author(s):  
Safaa I. Mohammed ◽  
Y. Al-Douri

The structural properties of Zn-doped and undoped lead iodide ( PbI2 ) nanostructures have been investigated. Zn-doped and undoped of ( PbI2 ) have been grown by chemical technique. Different doped and undoped PbI2 when prepared successfully by thermal evaporation technique an glass substrate at room temperature. Characterization and analysis using scanning electron microscopy (SEM) and X-ray diffraction (XRD) have indicated to the crystalline character. The particle size of Zn-PbI2 is larger than undoped PbI2.


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