scholarly journals New Insights into the Crystal Chemistry of Elpidite, Na2Zr[Si6O15]·3H2O and (Na1+YCax□1−X−Y)Σ=2Zr[Si6O15]·(3−X)H2O, and Ab Initio Modeling of IR Spectra

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2160
Author(s):  
Alexander Bogdanov ◽  
Ekaterina Kaneva ◽  
Roman Shendrik
Keyword(s):  
Ir Spectra ◽  
Structural Models ◽  
Chemical Characterization ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Special Group ◽  
X Ray ◽  
Influence Of Water ◽  
Radioactive Species

Elpidite belongs to a special group of microporous zirconosilicates, which are of great interest due to their capability to uptake various molecules and ions, e.g., some radioactive species, in their structural voids. The results of a combined electron probe microanalysis and single-crystal X-ray diffraction study of the crystals of elpidite from Burpala (Russia) and Khan-Bogdo (Mongolia) deposits are reported. Some differences in the chemical compositions are observed and substitution at several structural positions within the structure of the compounds are noted. Based on the obtained results, a detailed crystal–chemical characterization of the elpidites under study was carried out. Three different structure models of elpidite were simulated: Na2ZrSi6O15·3H2O (related to the structure of Russian elpidite), partly Ca-replaced Na1.5Ca0.25ZrSi6O15·2.75H2O (close to elpidite from Mongolia), and a hypothetical CaZrSi6O15·2H2O. The vibration spectra of the models were obtained and compared with the experimental one, taken from the literature. The strong influence of water molecule vibrations on the shape of IR spectra of studied structural models of elpidite is discussed in the paper.

Influence of the Residue of Casting by Lost Wax in the Modulus of Elasticity and Porosity of Concretes

2014 ◽  
Vol 805 ◽  
pp. 343-349
Author(s):  
Carine F. Machado ◽  
Weber G. Moravia
Keyword(s):  
Construction Industry ◽  
Modulus Of Elasticity ◽  
Chemical Characterization ◽  
Microstructural Characterization ◽  
Cement Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardened State ◽  
Material Powder

This work evaluated the influence of additions of the ceramic shell residue (CSR), from the industries of Lost Wax Casting, in the modulus of elasticity and porosity of concrete. The CSR was ground and underwent a physical, chemical, and microstructural characterization. It was also analyzed, the environmental risk of the residue. In the physical characterization of the residue were analyzed, the surface area, and particle size distribution. In chemical characterization, the material powder was subjected to testing of X-ray fluorescence (XRF). Microstructural characterization was performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The residue was utilized like addition by substitution of cement in concrete in the percentages of 10% and 15% by weight of Portland cement. It was evaluated properties of concrete in the fresh and hardened state, such as compressive strength, modulus of elasticity, absorption of water by total immersion and by capillarity. The results showed that the residue can be used in cement matrix and improve some properties of concrete. Thus, the CSR may contribute to improved sustainability and benefit the construction industry.

Mineralogical and geochemical characterization of archaeological ceramics from the 16th century El Badi Palace, Morocco

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 459-470
Author(s):  
Mouhssin El Halim ◽  
Lahcen Daoudi ◽  
Meriam El Ouahabi ◽  
Valérie Rousseau ◽  
Catherine Cools ◽  
...  
Keyword(s):  
Sixteenth Century ◽  
Chemical Characterization ◽  
Raw Material ◽  
Maximum Temperature ◽  
X Ray Diffraction ◽  
Archaeological Ceramics ◽  
Geochemical Characterization ◽  
X Ray ◽  
Firing Tests

ABSTRACTTextural, mineralogical and chemical characterization of archaeological ceramics (zellige) from El Badi Palace (Marrakech, Morocco), the main Islamic monument from the Saadian period (sixteenth century), has been performed to enhance restoration and to determine the technology of manufacturing. A multi-analytical approach based on optical and scanning electron microscopy, cathodoluminescence, X-ray fluorescence and X-ray diffraction was used. Re-firing tests on ceramic supports were also performed to determine the firing temperatures used by the Saadian artisans. A calcareous clay raw material was used to manufacture these decorative ceramics. The sherds were fired at a maximum temperature of 800°C in oxidizing atmosphere. The low firing temperature for ‘zellige’ facilitates cutting of the pieces, but also causes fragility in these materials due to the absence of vitreous phases.

Microstructure and Properties of Nanosemicrystalline Si3N4 Ceramics with Doped Sintering Additives: Part I. Microstructural Characterization of Nanosemicrystalline Si3N4 Powders

1998 ◽  
Vol 13 (9) ◽  
pp. 2580-2587 ◽  
Author(s):  
K. H. Ryu ◽  
J-M. Yang
Keyword(s):  
Microstructural Characterization ◽  
Degree Of Crystallinity ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Additives ◽  
Transmission Electron ◽  
Wet Chemical ◽  
Si3n4 Ceramics

The characteristics of nanosized silicon nitride powders with doped Y2O3 and Al2O3 fabricated by a plasma-reacted chemical process were investigated. The chemical compositions of the powders were analyzed by wet chemical analysis. The morphology and the size distribution were determined by transmission electron microscopy (TEM). TEM with energy dispersive spectroscopy (EDS) was used to verify the existence of sintering additives in each individual particle. The crystal structure of the powders was identified by the selected area diffraction pattern (SADP). X-ray diffraction (XRD) technique was used for phase analysis and the measurement of degree of crystallinity. The characteristics of chemical bonding was analyzed by using Fourier transform infrared spectroscopy (FTIR).

Mineralogical and chemical characterization of some vermiculites from the Mozambique Belt of Tanzania for agricultural use

Clay Minerals ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 1-17 ◽  
Author(s):  
E. M. M. Marwa ◽  
S. Hillier ◽  
C. M. Rice ◽  
A. A. Meharg
Keyword(s):  
Inductively Coupled Plasma ◽  
Crop Production ◽  
Chemical Characterization ◽  
Chemical Compositions ◽  
Accessory Minerals ◽  
X Ray ◽  
Mozambique Belt ◽  
Agricultural Use ◽  
Soil Conditioners

AbstractVermiculite minerals are locally available in the Mozambique Belt of Tanzania but are not currently commercially exploited. In part this may be due to lack of any precise characterization. This study was carried out as a first step to assess the suitability of these vermiculites for crop production by characterization of their mineralogical and chemical compositions. X-ray diffraction and scanning electron microscopy combined with an energy-dispersive X-ray system were used to establish the mineralogy. Electron microprobe analysis and inductively coupled plasma-mass spectrometry were used to study the chemical compositions and to identify any possible issues related to chemical composition that might affect their use if applied as soil conditioners. The samples were characterized as vermiculites and hydrobiotites with a wide variety of accessory minerals. Accessory minerals that might be of some concern are galena, fibrous amphiboles and sepiolite. The total levels of Ni in all vermiculites, and Cr in some, were also found to be high relative to common European standards and this might limit their potential as soil conditioners. It is clear that a field assessment of the bioavailability of various elements would be necessary before decisions relating to potential agricultural use could be made.

Structural and Chemical Characterization of Tungsten Gate Stack for 1 Gb Dram

2000 ◽  
Vol 611 ◽  
Author(s):  
O. Gluschenkov ◽  
J. Benedict ◽  
L.A. Clevenger ◽  
P. DeHaven ◽  
C. Dziobkowski ◽  
...  
Keyword(s):  
Side Wall ◽  
Chemical Characterization ◽  
X Ray Diffraction ◽  
Gate Stack ◽  
X Ray ◽  
Transition Electron Microscopy ◽  
Tungsten Crystal ◽  
Material Interaction ◽  
Transition Electron

ABSTRACTMaterial interaction during integration of tungsten gate stack for 1 Gb DRAM was investigated by Transition Electron Microscopy (TEM), X-ray Diffraction analysis (XRD) and Auger Electron Spectroscopy (AES). During selective side-wall oxidation tungsten gate conductor undergoes a structural transformation. The transformation results in the reduction of tungsten crystal lattice spacing, re-crystallization of tungsten and/or growth of grains. During a highly selective oxidation process, a relatively small but noticeable amount of oxygen was incorporated into the tungsten layer. The incorporation of oxygen is attributed to the formation of a stable WO x (x<2) composite.

Electronic Waste: Characterization of the Glass of Cathode Ray Tube Computer for Making Decorative Pieces by Recycling

2012 ◽  
Vol 727-728 ◽  
pp. 1525-1529
Author(s):  
N.M.O. Lima ◽  
Crislene Rodrigues da Silva Morais ◽  
L.M.R. Lima ◽  
A.V. Albuquerque
Keyword(s):  
Electronic Waste ◽  
Modern World ◽  
Chemical Compositions ◽  
Strontium Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Granulometric Analysis ◽  
Cathode Ray Tube ◽  
Computer Monitors

The vigorous industrialization of the modern world and the incorporation of new consumption habits of society made appears electronic waste. This work had as objective to collect and characterize vitreous residues originating from Cathode Ray Tubes or, popularly, "image tubes", identified for the acronym CRT, which integrate computers monitors that will be recycled in the production of handicrafts. For its characterization were used techniques: X-Ray Fluorescence, Granulometric Analysis, X-Ray Diffraction. After analyses it was observed that glasses of the screen and of the funnel presented different chemical compositions, being silicium oxide (SiO2) the component of larger percentage in these glasses, 59.89% and 48.63%, for screen and funnel, respectively. Funnel presented 29.47% of lead oxide (PbO) while this oxide is absent in the screen. Screen presents significant amounts of barium oxide (10.75%) and strontium oxide (7.71%). Vitreous samples X-ray diffractions of residues of the funnel and the screen are to each other similar, presenting an amorphous band that indicates silica presence, with absence of crystalline phases. Through the presented results can be concluded that computer monitors CRTs has potential for be recycled, because present great amounts of SiO2, oxide that forms the vitreous net.

scholarly journals Mineralogical, Physicochemical and Morphological Characterization of Okpella Clay

Mining Revue ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 78-82
Author(s):  
Nurudeen Salahudeen ◽  
Aminat Oluwafisayo Abodunrin
Keyword(s):  
Ph Value ◽  
Chemical Characterization ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
Local Clay ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Edo State ◽  
Fluorescence Analyzer

Abstract Local clay mineral was mined from Okpella Town, Etsako Local Government Area of Edo State, Nigeria. Mineralogical characterization of the clay was carried out using X-ray diffraction analyzer. Chemical characterization of the clay was carried out using X-ray fluorescence analyzer and the pH analysis of the clay was carried out using pH meter. The mineralogical analysis revealed that the clay was majorly a dolomite mineral having 72% dolomite. The impurities present are 18% cristobalite, 4.1% garnet, 5% calcite and 1% quicklime. The pH analysis of the clay revealed that the clay was acidic having average pH value of 3.9. The pH determined for the 1:1, 1:2, 1:4, 1:8 and 1:10 samples were 3.61, 3.85, 3.85, 4.05 and 4.09, respectively.

Preparation and Characterization of HGM-Ni0.5Co0.5Fe2O4 Core-Shell Particles by Homogeneous Coprecipitation

2013 ◽  
Vol 745-746 ◽  
pp. 293-297 ◽  
Author(s):  
Mei Yu ◽  
Jing Zhi Hu ◽  
Jian Hua Liu ◽  
Song Mei Li
Keyword(s):  
Spinel Ferrite ◽  
Magnetic Film ◽  
Core Shell ◽  
Chemical Compositions ◽  
Hollow Glass Microsphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coprecipitation Process ◽  
Shell Particles

HGM-Ni0.5Co0.5Fe2O4 core-shell particles were prepared by plating Ni0.5Co0.5Fe2O4 magnetic film on hollow glass microsphere (HGM) from the aqueous solution containing NiCl2·6H2O, FeCl2·4H2O, CoCl2·6H2O and HGMs without sintering. Urea was used as precipitator, and air was used as oxidizer in homogeneous coprecipitation process. The morphologies, phase structures, shell thickness, chemical compositions and magnetic performances of the core-shell particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and vibrating sample magnetometer (VSM), respectively. The results showed that a compact and continuous film with thickness at about 250 nm was coated on the HGM by the homogeneous coprecipitation process. The film was spinel ferrite phase, and was determined as the Ni0.5Co0.5Fe2O4. The saturation magnetization (Ms) and the coercivity (Hc) of as-synthesized HGM-Ni0.5Co0.5Fe2O4 core-shell particles were 20.886emu/g and 97.174G, respectively.

Characterization of Diatomite, Leonardite and Pumice

2016 ◽  
Vol 872 ◽  
pp. 211-215 ◽  
Author(s):  
Pusit Pookmanee ◽  
Atit Wannawek ◽  
Sakchai Satienperakul ◽  
Ratchadapon Putharod ◽  
Nattapol Laorodphan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Functional Group ◽  
Chemical Compositions ◽  
Carbonyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Properties Of Materials ◽  
Scanning Electron

This research studies compositions of diatomite, leonardite and pumice for utilization appropriate to the properties of materials. Chemical compositions of these materials were characterized by X–ray fluorescence spectrometry (XRF) and energy dispersive X–ray spectrometry (EDXS). The silica was major component of these materials. The morphology was investigated by scanning electron microscopy (SEM). Diatomite was cylindrical in shape, leonardite was sheet or flake in shape and pumicewas prismatic in shape. The structure was studied by X–ray diffraction (XRD). It was found that the mineral composition of diatomite, leonardite and pumice showed cristobalite low, quartz and anorthite, respectively. The functional groups were identified by Fourier transform infraredspectrometry (FTIR). The functional group of siloxane was obtained and dominated vibration in these materials. And the vibration of carboxylic, alcoholic and carbonyl groups were obtained in leonardite.

scholarly journals Development and Properties of New Mullite Based Refractory Grog

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 779
Author(s):  
David Zemánek ◽  
Karel Lang ◽  
Lukáš Tvrdík ◽  
Dalibor Všianský ◽  
Lenka Nevřivová ◽  
...  
Keyword(s):  
Raw Materials ◽  
High Alumina ◽  
Firing Process ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Microscopies ◽  
Alumina Refractory ◽  
Refractory Aggregate

The presented study is focused on optimization and characterization of a high-alumina refractory aggregate based on natural raw materials—kaolins, claystone, and mullite dust by-product (used to increase the alumina and mullite contents, respectively). In total, four individual formulas with the Al2O3 contents between 45 and 50 wt.% were designed; the samples were subsequently fired, both in a laboratory oven and an industrial tunnel furnace. The effects of repeated firing were examined during industrial pilot tests. Mineral and chemical compositions and microstructures, of both the raw materials and designed aggregates, were thoroughly investigated by the means of X-ray fluorescence spectroscopy, powder X-ray diffraction, and optical and scanning electron microscopies. Porosity, mineral composition, and mullite crystal-size development during the firing process were also studied. Based on the acquired results, the formula with the perspective to be used as a new mullite grog, featuring similar properties as the available commercial products, however, with reduced production expenses, was selected. The quality of grog determines to a large extent the properties of the final product. Hence, optimization of aggregates for specific refractories is of a great importance. The production of engineered aggregates provides the opportunity to utilize industrial by-products.

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