Carbonization Effect on Phase Structures of Zirconium Oxides with 2-3 Percent Yttrium

2014 ◽  
Vol 936 ◽  
pp. 181-186
Author(s):  
Zhi Qin Xue ◽  
Yong Quan Guo
Keyword(s):  
Tetragonal Phase ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zirconium Oxides ◽  
Percent Yttrium ◽  
Before And After ◽  
Cubic Structure ◽  
Diffraction Patterns ◽  
Rietveld Structural Refinement

Phase evolutions and structures of zirconium oxides with 2 percent yttrium before and after carbonization have been systemically studied with X-ray diffraction and Rietveld structural refinement. The carbonization decreases the structural stability of original ZrO2. According to the X-ray diffraction patterns, three phases with monoclinic, tetragonal and cubic structure coexist after carbonization. With increasing carbonizing temperature, the content of tetragonal phase in ZrO2with 2% mol Y2O3 doped increases，however, the phase content of monoclinic phase decreases. The content of tetragonal phase in ZrO2with 3% mol Y2O3doped increases greatly after carbonization. It implies that carbonization is beneficial for the formation of ZrO2tetragonal phase.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

scholarly journals Band Gap Tailoring, Size Modulation and Photoluminescence Properties of Mn/Cu doped ZnS Nanostructures

2021 ◽  
Author(s):  
P.J. Binu ◽  
S. Muthukumaran
Keyword(s):  
Energy Gap ◽  
Effective Control ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Cubic Structure ◽  
Diffraction Patterns ◽  
Co Precipitation ◽  
Band Gap Tailoring

Abstract ZnS, Mn added ZnS (Zn0.97Mn0.03S) and Mn, Cu dual doped ZnS (Zn0.95Mn0.03Cu0.02S) QDs have been prepared using co-precipitation technique. The influence of Mn and Cu addition on the morphology, structure and photoluminescence properties of Mn/Cu incorporated ZnS have been examined. Cubic structure of the synthesized samples was confirmed by X-ray diffraction patterns. The incorporation of Cu in Zn-Mn-S lattice not only decreased the particle/grain size and also generates more defect based luminescent activation centres. The reduced energy gap by Mn addition was explained by sp-d exchange interaction and the elevated energy gap in Cu, Mn dual doped ZnS was expalined by Burstein–Moss effect. The tuning phenomenon of size as well as the energy gap in ZnS by Mn/Cu addition promote these materials for nano-electronic applications. FTIR spectra confirmed the presence of Mn/Cr-Zn-S bondings. The substitution of Mn /Cu provides an effective control over tuning of different emission colours which signifies their applications like light emitting diodes.

scholarly journals Liquid-Phase Catalytic Oxidation of Limonene to Carvone over ZIF-67(Co)

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 374 ◽  
Author(s):  
Yizhou Li ◽  
Yepeng Yang ◽  
Daomei Chen ◽  
Zhifang Luo ◽  
Wei Wang ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Catalytic Oxidation ◽  
Heterogeneous Catalyst ◽  
Product Selectivity ◽  
X Ray Diffraction ◽  
Zeolitic Imidazolate Framework ◽  
X Ray ◽  
Mild Conditions ◽  
Before And After ◽  
Diffraction Patterns

Liquid-phase catalytic oxidation of limonene was carried out under mild conditions, and carvone was produced in the presence of ZIF-67(Co), cobalt based zeolitic imidazolate framework, as catalyst, using t-butyl hydroperoxide (t-BHP) as oxidant and benzene as solvent. As a heterogeneous catalyst, the zeolitic imidazolate framework ZIF-67(Co) exhibited reasonable substrate–product selectivity (55.4%) and conversion (29.8%). Finally, the X-ray diffraction patterns of the catalyst before and after proved that ZIF-67(Co) acted as a heterogeneous catalyst, and can be reused without losing its activity to a great extent.

Characterization of Cordierite Glass with the Addition Colorant Ceramic Glaze for FIR Therapy

2016 ◽  
Vol 840 ◽  
pp. 207-212
Author(s):  
Lim Yi Xuan ◽  
Johar Banjuraizah ◽  
Zainal Arifin Ahmad
Keyword(s):  
High Hardness ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
Porosity Level ◽  
X Ray ◽  
Refinement Method ◽  
Cordierite Glass ◽  
Crystallization Of Glass ◽  
Rietveld Structural Refinement

α-Cordierite glass ceramic was synthesised through crystallization of glass compacts made of milled glass frits. The effect of temperatures and colorants were studied. The crystal structure of α-cordierite was analysed using X-ray diffraction technique and Rietveld structural refinement method. Density, porosity and shrinkage analysis, Vickers hardness and SEM were also performed. The result revealed that at higher sintering temperatures, the properties of α-cordierite was getting better. Low apparent porosity level and high hardness dense α-cordierite was fabricated at temperature 1350oC. The low porosity level may lead to high thermal conductivity which suggested that cordierite was candidates for FIR therapy instrumemts.________________________________________________________________________

An Application of Multigrain Approaches to the Structural Solution of Grains from Polycrystalline Samples

2019 ◽  
Vol 288 ◽  
pp. 119-123 ◽  
Author(s):  
Jav Davaasambuu ◽  
Jon Wright ◽  
Henning O. Soerensen ◽  
Soeren Schmidt ◽  
Henning F. Poulsen ◽  
...  
Keyword(s):  
Structural Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Parameters ◽  
Resolution Level ◽  
Diffraction Patterns ◽  
The Individual ◽  
Individual Grains ◽  
Comparison Of The Results ◽  
Good Agreement

The overlap of diffraction spots from different grains was investigated to understand the influence of experimental factors on the x-ray diffraction data quality and to optimize the experimental parameters for data collection on polycrystalline samples. Diffraction patterns for photoactive polycrystals were indexed and sorted with respect to grains using multigrain approaches. The indexing of diffraction spots and the identification of grains for tetrathiafulvalene-p-chloranil samples were performed using the ImageD11, GrainSpotter, GRAINDEX and Cell_now programs. In many cases, comparison of the results from these programs shows good agreement. For the individual grains from polycrystalline samples, the crystal structure was solved and refined using the SHELXTL program. After the structural refinement of the grains, the best and the average R1 values were 1.93% and 2.06%, respectively, which are on a comparable resolution level with that obtained from the x-ray single crystal measurements.

Reactive Adsorption of Sulfur Compounds from FCC Gasoline on NiO/γ-Al2O3

2009 ◽  
Vol 79-82 ◽  
pp. 2219-2222 ◽  
Author(s):  
Hai Yan Yin ◽  
Chun Hu Li ◽  
Lin Xue Wang ◽  
Ying Min Yu
Keyword(s):  
Nitrogen Adsorption ◽  
Sulfur Compounds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fcc Gasoline ◽  
Reactive Adsorption ◽  
Before And After ◽  
Desulfurization Efficiency ◽  
Diffraction Patterns ◽  
Sulfur Adsorption

NiO/γ-Al2O3 adsorbent was prepared by wet impregnated method. XRD, SEM-EDS, nitrogen adsorption techniques were used to characterize the adsorbents and GC-FPD was utilized to analyze the composition of gasoline before and after reaction. X-ray diffraction patterns indicate that noncrystal NiO particles are supported on the surface of γ-Al2O3. The results show that NiO/γ-Al2O3 adsorbent could be used to remove sulfur compounds and is effective on removing benzothiophene (BT). The maximum desulfurization efficiency appears when NiO content reaches 16%, and the total sulfur adsorption capacity is 1.84mg/g, however for 16%Ni/γ-Al2O3 the value reaches 3.495mg/g.

scholarly journals Zinc containing borate glasses and glass-ceramics: Search for biomedical applications

2014 ◽  
Vol 8 (4) ◽  
pp. 185-193 ◽  
Author(s):  
Amr Abdelghany ◽  
Fatema Elbatal ◽  
Hatem Elbatal
Keyword(s):  
Glass Ceramic ◽  
Corrosion Behaviour ◽  
Glass Ceramics ◽  
Soda Lime ◽  
Dissolution Mechanism ◽  
Borate Glasses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After ◽  
Diffraction Patterns

Ternary soda lime borate glass and samples with ZnO replacing CaO up to 10mol%were prepared and studied for their bone bonding ability. Fourier transform infrared (FTIR) absorption spectra of the prepared glasses before and after immersion in simulated body fluid (SBF), for one or two weeks, showed the appearance of calcium phosphate (hydroxyapatite (HA)) which is an indication of bone bonding ability. X-ray diffraction patterns were measured for the glasses and indicated the presence of small peaks related to hydroxyapatite in the samples immersed in SBF. The glasses were heat treated with controlled two-step regime to convert them to their corresponding glass-ceramic derivatives. FTIR and X-ray diffraction measurements of the glass-ceramic samples (before and after immersion in SBF) confirmed the appearance of HA which is influenced by ZnO content. The overall data are explained on the basis of current views about the corrosion behaviour of borate glasses including hydrolysis and direct dissolution mechanism.

X-Ray Diffraction Patterns of Oil Palm Empty Fruit Bunch Fibers with Varying Crystallinity

2015 ◽  
Vol 1087 ◽  
pp. 321-328 ◽  
Author(s):  
Fatin Afifah Ahmad Kuthi ◽  
Khairiah Haji Badri ◽  
Azlin Mohmad Azman
Keyword(s):  
Acid Hydrolysis ◽  
Oil Palm ◽  
Empty Fruit Bunch ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Before And After ◽  
Different Temperatures ◽  
Diffraction Patterns ◽  
Xrd Patterns

Crystallinity of oil palm fiber from empty fruit bunch (EFB) with and without tretaments was studied by analyzing the X-ray diffraction (XRD) pattern. In this paper, we focused on the effect of acid hydrolysis onto EFB on the crystallinity of the extracted cellulose. The reaction was carried out by soaking EFB in 1% (v/v) aqueous sulfuric acid (H2SO4) at different temperatures of 120, 130 and 140°C for 1 h. The XRD patterns significantly showed changes in the 2θ peaks before and after the treatment. These changes were described in term of polymorphs type present, reflection and allomorphs of the samples. XRD peak high and XRD deconvolution methods were used to calculate and compare the percentage of crystallinity of untreated EFB (UT-EFB) and acid hydrolyzed samples (AH-EFB). Based on the calculation, increment of about 1.3 times and 1.5 times were achieved by using WAXS and XRD deconvolution methods respectively. This is due to the removal of amorphous part contributed by lignin, hemicellulose and cellulose. Fourier Transform infrared (FTIR) spectra showed the presence of similar peaks in AH-EFB and commercial microcrystalline cellulose (C-MCC) at 1427, 1315, 895 and 1022 cm-1. The micrographic features showed the acid hydrolysis had successfully took place and separated the EFB microfibrils bundles.

Rietveld structural refinement of «A» type phosphostrontium carbonate hydroxyapatites

2013 ◽  
Vol 28 (S2) ◽  
pp. S409-S424 ◽  
Author(s):  
Sonia Jebri ◽  
Habib Boughzala ◽  
Ali Bechrifa ◽  
Mohamed Jemal
Keyword(s):  
Infrared Spectroscopy ◽  
Structural Model ◽  
Structural Refinement ◽  
Interatomic Distances ◽  
X Ray ◽  
Crystallographic Study ◽  
Different Temperatures ◽  
Diffraction Patterns ◽  
The One ◽  
Rietveld Structural Refinement

Phosphostrontium carbonate hydroxyapatites having the general formula Sr10(PO4)6(OH)(2-2x)(CO3)x were prepared by solid gas reaction at different temperatures in the range 0 ≤ x ≤ 1. Infrared spectroscopy investigation reveals a carbonate groups substituting hydroxyl ions. Intensity bands increasing with the carbonate amount introduced in the lattice, while the one corresponding to hydroxyl decreases until disappearance. The Rietveld refinement of the structural model using X-ray powder diffraction patterns is used to determine the substitution rate. It was quantified by the refinement of the occupancy sites affected by the substitution. The crystallographic study shows the evolution of the atomic coordinate in the apatite due to the carbonate incorporation. The variation of the main interatomic distances and the bond angles was also discussed.

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