scholarly journals Growth and Characterization of ULMA Single Crystals Doped with Ammonium Chloride

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
B. Sivasankari ◽  
P. Selvarajan

Single crystals of pure and ammonium chloride-doped urea L-malic acid (ULMA) were grown by slow evaporation technique. Many interesting results on several properties of ammonium chloride impurity added to ULMA single crystals have been observed and studied. The different morphology of ammonium chloride-doped ULMA crystals was noticed and the effect of ammonium chloride doping on the growth, optical, and hardness properties has been investigated. The presence of functional groups has been estimated by FTIR analysis. The lattice parameters of the grown crystals were studied by single crystal X-ray diffraction technique. Powder X-ray diffraction studies confirm the diffraction planes of the grown crystals. The UV-visible spectrum shows the cutoff wavelength at 220 nm. A study on the thermal properties has also been carried out. The NLO property of the grown crystals was confirmed by SHG studies.

2012 ◽  
Vol 602-604 ◽  
pp. 917-920 ◽  
Author(s):  
Zhen Hui Xiao ◽  
Shui Sheng Wu ◽  
Yan Lin Sun ◽  
Yu Lin Zhao ◽  
Ya Ming Wang

Graphene was synthesized by microwave-hydrothermal chemical reduction of graphite oxide using hydrazine hydrate as the reducing agent. Graphene was characterized using X-ray diffraction, UV-visible spectrum, FT-IR spectrum and scanning electron microscopy. Results indicated that the as-prepared graphene was wrinkled and comprised fewer graphenes with a highly crystalline structure.


2007 ◽  
Vol 21 (29) ◽  
pp. 2025-2032 ◽  
Author(s):  
T. BARANIRAJ ◽  
P. PHILOMINATHAN ◽  
N. VIJAYAN

Single crystals of para Nitroaniline ( pNA ), an organic nonlinear optical (NLO) material, have been grown by slow solvent evaporation technique at room temperature. Good optical quality single crystals with dimensions of up to 10 × 11 × 3 mm 3 have been grown by adopting the above technique, and good quality single crystals were obtained. The grown single crystals were subjected to different characterization analyses. The lattice dimensions have been determined from the powder X-ray diffraction analysis. Its functional groups and optical behavior have been identified from the FTIR and UV-Vis. analyses respectively. The thermal stability of the crystal has been analyzed by thermogravimetric (TG) and differential thermal (DT) analyses respectively.


2011 ◽  
Vol 299-300 ◽  
pp. 722-726
Author(s):  
Wen Chang Zhuang ◽  
Yu Xiao Wang

Composites have achieved much attention because of their excellent qualities. Core-shell γ-Fe2O3/Au nanoparticles were prepared by chemical reduction. Their optical properties and morphology were characterized by UV-visible spectrum (UV-vis), X-ray diffraction (XRD) and Transmission Electronic Microscopy (TEM). Furthermore, the average particle size and interface structure were also analyzed using small angle X-ray scattering (SAXS).


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).


2017 ◽  
Vol 6 (1) ◽  
pp. 62-68
Author(s):  
S. Vetrivel ◽  
R. U. Mullai ◽  
K. Kanagasabapathy ◽  
R. Aruljothi ◽  
V. Praveenkumar

Semiorganic optically transparent Bis(4-nitrobenzoate) tetraaquamanganese (II) dihydrate [Mn (p-NO2C6H4COO)2 (H2O)4]·2H2O (BNMD) single crystals were grown by slow evaporation technique at room temperature. Single crystal X-ray diffraction analysis was carried out to determine the lattice parameters of the crystal. Powder X-ray diffraction pattern was recorded and indexed for the structural confirmation. The crystalline quality was confirmed by HRXRD. The presence of functional group in the compound has been confirmed by FTIR analysis. UV-Visible transmission spectrum has been recorded to determine the cut-off wavelength region of the crystal. The Second Harmonic Generation of BNMD crystal was confirmed by Kurtz-Perry powder method using Nd:YAG laser and found to be 0.59 times that of KDP. The dielectric response of the crystal was also investigated and reported. The microhardness study reveals that the hardness number (Hv) increases with load. From the values of work hardening coefficients, it was concluded that BNMD crystal belong to the category of soft materials. Thermal studies were performed using differential thermal analysis (DTA).


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.


1997 ◽  
Vol 07 (03n04) ◽  
pp. 265-275
Author(s):  
R. Q. Zhang ◽  
S. Yamamoto ◽  
Z. N. Dai ◽  
K. Narumi ◽  
A. Miyashita ◽  
...  

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.


2013 ◽  
Vol 665 ◽  
pp. 254-262 ◽  
Author(s):  
J.R. Rathod ◽  
Haresh S. Patel ◽  
K.D. Patel ◽  
V.M. Pathak

Group II-VI compounds have been investigated largely in last two decades due to their interesting optoelectronic properties. ZnTe, a member of this family, possesses a bandgap around 2.26eV. This material is now a day investigated in thin film form due to its potential towards various viable applications. In this paper, the authors report their investigations on the preparation of ZnTe thin films using vacuum evaporation technique and their structural and optical characterizations. The structural characterization, carried out using an X-ray diffraction (XRD) technique shows that ZnTe used in present case possesses a cubic structure. Using the same data, the micro strain and dislocation density were evaluated and found to be around 1.465×10-3lines-m2and 1.639×1015lines/m2respecctively. The optical characterization carried out in UV-VIS-NIR region reveals the fact that band gap of ZnTe is around 2.2eV in present case. In addition to this, it was observed that the value of bandgap decreases as the thickness of films increases. The direct transitions of the carries are involved in ZnTe. Using the data of UV-VIS-NIR spectroscopy, the transmission coefficient and extinction coefficient were also calculated for ZnTe thin films. Besides, the variation of extinction coefficient with wavelength has also been discussed here.


Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.


2012 ◽  
Vol 727-728 ◽  
pp. 1473-1478
Author(s):  
Mariaugusta Ferreira Mota ◽  
Fabricio Machado ◽  
Meiry Glaúcia Freire Rodrigues

This work presents an experimental study focusing on the preparation and characterization of modified natural green clay-mud with quaternary ammonium salts of chloride and alkyl dimethyl benzyl ammonium chloride (Dodigen) and dimethyl stearyl ammonium chloride (Praepagen). X ray Diffraction (XRD), infrared spectroscopy (IR) and expansion tests (adsorption capacity and Foster swelling) measurements were performed in order to evaluate the performance of the ion exchange reactions and the degree of affinity with oil products. It is observed an increasing in the XRD basal spacing of the modified clays (1.96 nm and 2.25 nm for Praepagen and Dodigen salts, respectively) in comparison to the observed value (1.56 nm) for the natural clay. The IR results showed that salts were successfully incorporated to natural clay structure. Based on the expansion tests the organoclays presented the best efficiency independent on the kind of solvent used in comparison with the natural clay performance.


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