scholarly journals Fe-Al Phosphate Microcrystals in Pedogenic Goethite Pisoliths

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 357
Author(s):  
János Kovács ◽  
Éva Farics ◽  
Péter Szabó ◽  
István Sajó
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Fluorescence Spectroscopy ◽  
Powder Diffraction ◽  
Sedimentary Rocks ◽  
Depositional Environments ◽  
Substantial Contribution ◽  
Subtropical Climate ◽  
X Ray ◽  
Scanning Electron

In sedimentary rocks, Fe-Al phosphate minerals occur in different rocks and depositional environments. Herein, we present microcrystals of wavellite, crandallite, and cacoxenite from pedogenic goethite pisoliths and nodules. Pisoliths and nodules are generally dominated by Fe oxides and oxihydroxides. Frequently, pisoliths and nodules demonstrate high phosphatization and a substantial contribution of allogenic detritus. The aim of our study is to present these remarkable crystals found in goethites. We describe the geochemistry and mineralogy of the pisoliths and try to interpret the possible paragenesis of the minerals. Loose ferruginous pisoliths and nodules are separated from the red paleosol and analyzed using field emission scanning electron microscope (FE-SEM) coupled with the energy dispersive X-ray detector (EDS), X-ray fluorescence spectroscopy (XRF), and X-ray powder diffraction (XRD) methods. The studied paleosols are weathered in a subtropical climate and the newly formed precipitation products, such as crandallite, wavellite, cacoxenite, and goethite, accumulate during the weathering of apatite.

scholarly journals The influence of metahalloysite addition on tobermorite formation studied by X-ray powder diffraction and scanning electron microscope

2018 ◽  
Vol 163 ◽  
pp. 05008
Author(s):  
Anna Skawińska
Keyword(s):  
Phase Composition ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hydrothermal Treatment ◽  
Powder Diffraction ◽  
Quartz Sand ◽  
Raw Material ◽  
Model Systems ◽  
X Ray ◽  
Scanning Electron

This paper presents the results of the studies carried out in the model systems and concerning the tobermorite synthesis with an addition of metahalloysite. Quartz sand and quicklime were the main raw material constituents. The mixtures in the form of slurries underwent hydrothermal treatment with an addition of metahalloysite (5%, 10%, 15%, 20% and 30%) for 4 hours and 12 hours. The resultant composites were analysed for their phase composition using X-ray powder diffraction. The microstructure was examined using the Scanning Electron Microscope. Tobermorite was the principle reaction product. When 30% metahalloysite was added to the mixture containing CaO and SiO2, the formation of katoite was found.

scholarly journals Facile and Surfactant-Free Synthesis of Hierarchical ZnO Microstructures

2015 ◽  
Vol 19 (2) ◽  
pp. 17
Author(s):  
Kezhen Qi ◽  
Ruidan Wang ◽  
Jiaqi Fu ◽  
Ke Chen ◽  
Chunying Zuo
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Powder Diffraction ◽  
Growth Mechanism ◽  
Hydrothermal Route ◽  
X Ray ◽  
Reaction Solution ◽  
Facile Hydrothermal Route ◽  
Scanning Electron

Hierarchical ZnO crystals with flower-like microstructures were successfully synthesized via a facile hydrothermal route without using any surfactants. The morphology of these microstructures can be easily controlled by adjusting the pH of the reaction solution. The products were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM). Furthermore, a possible growth mechanism of ZnO hierarchical microstructures was proposed.  

scholarly journals Hybrid Ag2O/ZnO Heterostructures

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Wang ◽  
Yang Liu ◽  
Yang Jiao ◽  
Fengyu Qu ◽  
Qingzhi Pan ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Powder Diffraction ◽  
Growth Mechanism ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Step Procedure ◽  
Intrinsic Emission ◽  
Scanning Electron

The well-aligned Ag2O/ZnO microflowers heterostructure was synthesized by a straightforward two-step procedure. The diameters of the as-synthesized products were as much as 1.5 μm. The as-grown Ag2O/ZnO heterostructure was investigated by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and photoluminescence (PL) spectroscopy analysis. A possible growth mechanism for flowerlike Ag2O/ZnO heterostructure was proposed based on the experimental results. Compared with pure ZnO microflowers, PL spectrum of the composite with only one strong peak at 383 nm showed good intrinsic emission.

The Role of Alum in the Fabrication of Calcium Silicate for Dissolved Acetylene Cylinders

2011 ◽  
Vol 117-119 ◽  
pp. 870-872
Author(s):  
Shi Cai Cui ◽  
Zhao Bo Meng
Keyword(s):  
Phase Composition ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Powder Diffraction ◽  
Calcium Silicate ◽  
Filling Material ◽  
X Ray ◽  
Comprehensive Performance ◽  
Scanning Electron

Calcium silicate for filling material used in dissolved acetylene cylinders was prepared by adding alum as additive. Samples were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM). The effects of alum on the bleeding, shrinkage, strength, porosity, morphology and phase composition were studied. The experimental results show that the adding of alum can improve the comprehensive performance of samples. The mechanism was discussed in detail.

scholarly journals The Role of Aragonite in Producing the Microstructural Diversity of Serpulid Skeletons

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1435
Author(s):  
Olev Vinn
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Powder Diffraction ◽  
Deep Ocean ◽  
X Ray ◽  
Prismatic Structure ◽  
Wide Range ◽  
Different Types ◽  
Scanning Electron

Aragonite plays an important role in the biomineralization of serpulid polychaetes. Aragonitic structures are present in a wide range of serpulid species, but they mostly belong to one clade. Aragonitic structures are present in a wide range of marine environments, including the deep ocean. Aragonitic tube microstructures were studied using a scanning electron microscope. X-ray powder diffraction was used to identify the aragonite. Aragonite is used to build five different types of microstructures in serpulid tubes. The most common aragonitic irregularly oriented prismatic structure (AIOP) is also, evolutionarily, the most primitive. Some aragonitic microstructures, such as the spherulitic prismatic (SPHP) structure, have likely evolved from the AIOP structure. Aragonitic microstructures in serpulids are far less numerous than calcitic microstructures, and they lack the complexity of advanced calcitic microstructures. The reason why aragonitic microstructures have remained less evolvable than calcitic microstructures is currently unknown, considering their fit with the current aragonite sea conditions (Paleogene–recent).

Direct growth of Mn0.6Ni0.4CO3 nanosheet assembles on Ni foam for high-performance supercapacitor electrodes

2022 ◽  
Author(s):  
RongMin Cheng ◽  
Conghong Zhan ◽  
Juanjuan Gao
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Powder Diffraction ◽  
High Performance ◽  
Ni Foam ◽  
X Ray ◽  
Transmission Electron ◽  
Direct Growth ◽  
Calcination Treatment ◽  
Scanning Electron

Using Ni foam as a template, Mn0.6Ni0.4CO3 nanosheet assembles were synthesized by hydrothermal method and calcination treatment. X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Inductively...

scholarly journals Characterisation of Polymesoda bengalensis Shell Powder

2020 ◽  
Vol 7 (1) ◽  
pp. 500-509
Author(s):  
Mahsuri Yusof ◽  
Nur Tahirah Razali ◽  
Nicholas H. T. Kuan ◽  
Dexter Sigan John
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Powder Diffraction ◽  
Lamellar Structure ◽  
Energy Dispersive ◽  
Elemental Content ◽  
X Ray ◽  
Xrd Study ◽  
Shell Powder ◽  
Scanning Electron

The objectives of this research are to determine the element and polymorph of Polymesoda bengalensis shell and to compare its result with other bivalve shells. The polymorph of the powder was identified by X-ray powder diffraction (XRD) and its morphology was observed through scanning electron microscope (SEM). The XRD study revealed that the shell powder consisted entirely of aragonite. The analysis from SEM also revealed that the aragonite was in the form of rod-like crystal. The morphology of sectional, inner and outer surfaces of the shell was scanned using SEM. It was found that the aragonite was arranged in the form of a cross-lamellar structure of various sizes. The elemental content of the shell was examined using energy-dispersive X-ray spectroscopy (EDX). The result showed that CaCO3 in this shell contained large amounts of calcium and carbon.

Solidification Rate Influence on Microstructure of Composites with Quasicrystal Phase Fraction

2013 ◽  
Vol 203-204 ◽  
pp. 48-51
Author(s):  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Powder Diffraction ◽  
Solidification Rate ◽  
Structural Perfection ◽  
X Ray ◽  
The Matrix ◽  
Metallographic Observation ◽  
Laue Method ◽  
Scanning Electron

The composites of Al61Cu27Fe12alloys containing quasicrystalline and crystalline phases (CQ composites) were obtained by the Bridgman method. The morphology of composites crystallized with different solidification rates was studied. The solidification rate influence on fibrous reinforcement morphology was analyzed. The microsections for analysis were prepared parallel and perpendicular to the direction of crystallization. The optical and the scanning electron microscope were used for metallographic observation. Obtained composites were examined by X-ray powder diffraction and reflective X-ray topography. The Laue method enabled to conclude that the matrix is singlecrystalline. The different level of structural perfection of reinforcement fibres was presented at various solidification rates.

Influence of Calcining Temperature on the Microstructure of LaPO4 Powders

2009 ◽  
Vol 79-82 ◽  
pp. 2231-2234
Author(s):  
Zi Feng Liu ◽  
Xin Wang ◽  
Yan Sheng Yin ◽  
Qiang Liu
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Powder Diffraction ◽  
Grain Shape ◽  
Raw Materials ◽  
Precipitation Method ◽  
X Ray ◽  
Direct Precipitation ◽  
Direct Precipitation Method ◽  
Scanning Electron

Nanometer LaPO4 powders were synthesized by liquid-liquid direct precipitation method. La(NO3)3•6H2O and (NH4)3PO4•3H2O were used as raw materials. The calcining temperature was 900°C, 1000°C, 1100°C, respectively. DTA result shows that the LaPO4 precursor is LaPO4•4H2O. The calicined powders were characterized by X-ray powder diffraction (XRD) and Scanning Electron Microscope (SEM), and exhibited a pure LaPO4 phase with a monazite structure about 50-100 nm in diameter size. With the calcining temperature increasing, the crystallization of the LaPO4 became better and the grain shape changed from elongated grain shape to spherical grain shape.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

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