Preparation of Nanocrystalline γ-Alumina Using Ultrasonic Technique

The γ-alumina powder is a potential material for washcoat application. This paper shows the preparation of γ-alumina using ultrasonic technique in order to obtain nanocrystalline of γ-alumina powder. The 50 gr of the γ-alumina powders was treated in the 250 gr ethanol solution using ultrasonic technique within 10, 20, 30, and 60 minutes, respectively. The process of sonication was set at the fixed frequency (18.520 kHz) and current of 2 A. Crystallite size was evaluated by using X-ray diffraction (XRD) data based with Scherrer analysis and Williamson-Hall method. The microstructural characterization of the γ-alumina powders was observed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) analysis. The result shows that the optimum of nanocrystalline size of γ-alumina at ultrasonic process for 30 minutes are approximately 4.80 nm and 29.50 nm with Scherrer and Williamson-Hall calculation, respectively.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.805.343 ◽

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.

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Microstructural Characterization of Thin Polycrystalline Films by X-ray Diffraction

Advances in X-Ray Analysis ◽

10.1007/978-1-4613-1035-8_14 ◽

1988 ◽

pp. 129-142 ◽

Cited By ~ 2

Author(s):

C. N. J. Wagner ◽

M. S. Boldrick ◽

L. Keller

Keyword(s):

Microstructural Characterization ◽

Polycrystalline Films ◽

X Ray Diffraction ◽

X Ray ◽

Thin Polycrystalline

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Molecular and microstructural characterization of lecithin-based oleogels made with vegetable oil

RSC Advances ◽

10.1039/c6ra04324k ◽

2016 ◽

Vol 6 (53) ◽

pp. 47373-47381 ◽

Cited By ~ 19

Author(s):

Maxime Bodennec ◽

Qing Guo ◽

Dérick Rousseau

Keyword(s):

Vegetable Oil ◽

Small Angle ◽

Microstructural Characterization ◽

X Ray Diffraction ◽

X Ray ◽

3D Network

Lecithin-based oleogels consist of a worm-like entangled fibrous 3D network. Small angle X-ray diffraction suggests that these microfibres are formed by the packing of reverse hexagonal (HII) tubules parallel to the axis of fibres.

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Characterization of Pr-Doped LaF3 Nanoparticles Synthesized by Different Variations of Coprecipitation Method

Journal of Nanomaterials ◽

10.1155/2019/7549325 ◽

2019 ◽

Vol 2019 ◽

pp. 1-17 ◽

Cited By ~ 8

Author(s):

M. S. Pudovkin ◽

D. A. Koryakovtseva ◽

E. V. Lukinova ◽

S. L. Korableva ◽

R. Sh. Khusnutdinova ◽

...

Keyword(s):

Electron Microscopy ◽

Optical Spectroscopy ◽

Coprecipitation Method ◽

Luminescence Lifetime ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Hall Method ◽

Stoichiometric Proportion

A set of Pr3+:LaF3 nanoparticles (NPs) were synthesized via coprecipitation method at three stoichiometric proportions of La(NO3)3, Pr(NO3)3, and NaF (1 : 0.8, 1 : 1, and 1 : 6, respectively). Two ways of mixing of the La(NO3)3, Pr(NO3)3, and NaF solutions (dropwise and swift addition) were used. One sample was subjected to microwave (MW) treatment for 30, 90, and 180 min. All the samples were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). For all the samples, optical spectroscopy experiments were carried out. The XRD data were analyzed via the Debye-Scherrer and Williamson-Hall methods. It was revealed that the way of mixing of the La(NO3)3, Pr(NO3)3, and NaF solutions strongly affects the shape of the NPs. The slow dropwise addition of the NaF solution leads to the plate-like NP (PLNP) formation; otherwise, the swift addition of the NaF solution leads to the formation of more sphere-like NPs (SLNPs). The size and regularity in shape of the NP increase with the increasing stoichiometric proportion of La(NO3)3, Pr(NO3)3, and NaF from 1 : 0.8 to 1 : 6. The size and regularity in shape of the SLNPs increase with the increasing time of MW treatment. The Debye-Scherrer and Williamson-Hall methods confirmed the anisotropic shape of the PLNPs. The Williamson-Hall method showed that the values of strain are almost similar for all the samples (around 14∗10-4). Optical spectroscopy experiments revealed that although all the samples have an equal chemical composition, the luminescence lifetimes for different samples differ between each other. The luminescence lifetime of the PLNPs is less than that of the SLNPs having an equal stoichiometric proportion of La(NO3)3, Pr(NO3)3, and NaF. The luminescence lifetime of the 1 : 1 SLNPs increases with the increasing time of MW treatment.

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Microstructural Characterization of Glass-to-Metal Brazed Joint

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.616-618.1732 ◽

2012 ◽

Vol 616-618 ◽

pp. 1732-1735 ◽

Cited By ~ 1

Author(s):

Xi Hai Shen ◽

Yu Gang Zheng ◽

Liang Chang ◽

Jin Jia Guo ◽

Song Bin Ye ◽

...

Keyword(s):

Thermal Power ◽

Microstructural Characterization ◽

Xrd Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Solar Thermal Power ◽

Brazed Joints ◽

Brazed Joint ◽

Scanning Electron

Aiming at the glass-to-metal seals serving in the Solar Thermal Power (STP), glass-to-metal vacuum brazed joints were studied. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were performed to examine the microstructure and element contents of interface seam on the glass-to-metal vacuum brazed joints. Also, the compositional concentration of the interface seam was measured by using energy dispersive spectroscopy (EDS).

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Microstructural Characterization of Ornamental Rock Samples: Cariri Rocks

Materials Science Forum ◽

10.4028/www.scientific.net/msf.869.159 ◽

2016 ◽

Vol 869 ◽

pp. 159-163

Author(s):

Danúbia Lisbôa da Costa ◽

Ingrid Mayara Medeiros Fernandes ◽

Aluska Nascimento Simões Braga ◽

Rosiane Maria da Costa Farias ◽

Romualdo Rodrigues Menezes ◽

...

Keyword(s):

Chemical Analysis ◽

Microstructural Characterization ◽

Magnesium Carbonate ◽

X Ray Diffraction ◽

X Ray ◽

Mineral Sector ◽

Microstructural Heterogeneity ◽

Calcium And Magnesium ◽

Application Fields

Ornamental rocks are among the most promising business areas of the mineral sector, raising the necessity for, besides beauty, investments in quality, safety and characterization in the various application fields of these rocks. So, this work aims at the microstructural characterization of the class of these rocks: the Cariri Rocks, also known the limestone, which are calcareous rocks mainly formed by calcium and magnesium carbonate, possibly presenting variations due to their origins. For characterization, we studied four samples, being two from Chapada do Apodi and two from Chapada do Araripe, characterized physically and micro-structurally through chemical analysis, X-ray diffraction, optical micrography and porosimetry tests. The results prove that the limestones are calcitic and dolomitic, and present porosity varying from 5 to 15%, with pores concentration between 100nm and 10μm, besides the high microstructural heterogeneity.

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

Journal of Materials Research ◽

10.1557/jmr.1998.0360 ◽

1998 ◽

Vol 13 (9) ◽

pp. 2580-2587 ◽

Cited By ~ 4

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).

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X-ray diffraction studies of the decomposition and microstructural characterization of cold-worked powders of Cu–15Ni–Sn alloys by Rietveld analysis

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2003.10.019 ◽

2004 ◽

Vol 377 (1-2) ◽

pp. 103-116 ◽

Cited By ~ 33

Author(s):

P. Sahu ◽

S.K. Pradhan ◽

M. De

Keyword(s):

Microstructural Characterization ◽

Rietveld Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Cold Worked

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Microstructural Characterization of Ba2YCu3O7 Films Produced by Co-Evaporation

MRS Proceedings ◽

10.1557/proc-99-703 ◽

1987 ◽

Vol 99 ◽

Cited By ~ 2

Author(s):

G. J. Fisanick ◽

P. Mankeewicht ◽

W. Skocpolt ◽

R. E. Howardt ◽

A. Dayem ◽

...

Keyword(s):

Plane Surface ◽

Depth Profiling ◽

Microstructural Characterization ◽

Areal Density ◽

Oxygen Stoichiometry ◽

X Ray Diffraction ◽

X Ray ◽

Annealing Conditions ◽

Auger Microscopy

ABSTRACTBa2YCu3O7 films produced by co-evaporation of BaF2, Cu and Y onto <100> S1TiO3 substrates in an O2 ambient followed by post-annealing were analyzed using RBS, X-ray diffraction and Auger microscopy. These films exhibit Tc's (R=0) of =90K and a best Jc of > 1.0×106 A/cm2 at 81K for a =2500A thick film. RBS and Auger depth profiling limit the level of F present in the post-annealed films to <5 at. %, although F is evident in the as-deposited material. RBS channeling experiments yield a Xmin=31%, demonstrating the epitaxial quality of the films. X-ray diffraction shows that the films are predominantly oriented with c-axis perpendicular to the substrate, with narrow mosaic spread in-plane. A small portion of the film is in the form of needles oriented with a-axis perpendicular to the substrate, whose areal density is dependent on annealing conditions and local film stoichiometry. Scanning Auger microscopy confirms that the needles and c-axis plateaus have the same metal and oxygen stoichiometry. Also present in the film are insulating balls which appear to nucleate terraces in the c-axis perpendicular structure. Scanning Auger shows that these features are also close to the metals stoichiometry, but are C rich compared to the needles. The plateaus are covered with =11 times more C than the needles, indicating that the basal plane surface is highly reactive. Auger depth profiling and RBS show little evidence for interdiffusion.

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