scholarly journals New minerals tsangpoite Ca5(PO4)2(SiO4) and matyhite Ca9(Ca0.5□0.5)Fe(PO4)7 from the D'Orbigny angrite

2018 ◽  
Vol 83 (02) ◽  
pp. 293-313 ◽  
Author(s):  
Shyh-Lung Hwang ◽  
Pouyan Shen ◽  
Hao-Tsu Chu ◽  
Tzen-Fu Yui ◽  
Maria-Euginia Varela ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Raman Spectroscopy ◽  
Electron Diffraction ◽  
Grain Boundary ◽  
Electron Probe ◽  
Formation Mechanisms ◽  
Formula Unit ◽  
Micro Raman Spectroscopy ◽  
The Common ◽  
Oxygen Atoms

AbstractTsangpoite, ideally Ca5(PO4)2(SiO4), the hexagonal polymorph of silicocarnotite, and matyhite, ideally Ca9(Ca0.5□0.5)Fe(PO4)7, the Fe-analogue of Ca-merrillite, were identified from the D'Orbigny angrite meteorite by electron probe microanalysis, electron microscopy and micro-Raman spectroscopy. On the basis of electron diffraction, the symmetry of tsangpoite was shown to be hexagonal,P63/morP63, witha= 9.489(4) Å,c= 6.991(6) Å,V= 545.1(6) Å3andZ= 2 for 12 oxygen atoms per formula unit, and that of matyhite was shown to be trigonal,R3c, witha= 10.456 (7) Å,c= 37.408(34) Å,V= 3541.6 (4.8) Å3andZ= 6 for 28 oxygen atoms per formula unit. On the basis of their constant association with the grain-boundary assemblage: Fe sulfide + ulvöspinel + Al–Ti-bearing hedenbergite + fayalite–kirschsteinite intergrowth, the formation of tsangpoite and matyhite, along with kuratite (the Fe-analogue of rhönite), can be readily rationalised as crystallisation from residue magmas at the final stage of the D'Orbigny meteorite formation. Alternatively, the close petrographic relations between tsangpoite/matyhite and the resorbed Fe sulfide rimmed by fayalite + kirschsteinite symplectite, such as the nucleation of tsangpoite in association with magnetite ± other phases within Fe sulfide and the common outward growth of needle-like tsangpoite or plate-like matyhite from the fayalite–kirschsteinite symplectic rim of Fe sulfide into hedenbergite, infer that these new minerals and the grain-boundary assemblage might represent metasomatic products resulting from reactions between an intruding metasomatic agent and the porous olivine–plagioclase plate + fayalite-kirschsteinite overgrowth + augite + Fe sulfide aggregates. Still further thermochemical and kinetics evidence is required to clarify the exact formation mechanisms/conditions of the euhedral tsangpoite, matyhite and kuratite at the grain boundary of the D'Orbigny angrite.

Study of Triangle-Shaped Defects on Nearly On-Axis 4H-SiC Substrates

2016 ◽  
Vol 858 ◽  
pp. 225-228 ◽  
Author(s):  
Ren Wei Zhou ◽  
Xue Chao Liu ◽  
Hui Jun Guo ◽  
H.K. Kong ◽  
Er Wei Shi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
High Resolution ◽  
Optical Microscopy ◽  
Epitaxial Growth ◽  
Surface Defects ◽  
Micro Raman Spectroscopy ◽  
Transmission Electron

Triangle-shaped defects are one of the most common surface defects on epitaxial growth of 4H-SiC epilayer on nearly on-axis SiC substrate. In this paper, we investigate the feature and structure of such defects using Nomarski optical microscopy (NOM), micro-Raman spectroscopy and high resolution transmission electron microscopy (HR-TEM). It is found that triangle-shaped defects were composed of a thick 3C-SiC polytype, as well as 4H-SiC epilayer.

Non-Destructive Assessment of Thin Film Stresses and Crystal Qualify of Silicon on Insulator Materials with Raman Spectroscopy

1990 ◽  
Vol 188 ◽  
Author(s):  
Ingrid De Wolf ◽  
Jan Vanhellemont ◽  
Herman E. Maes
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Raman Spectroscopy ◽  
Cross Section ◽  
Silicon Layer ◽  
Silicon On Insulator ◽  
Micro Raman Spectroscopy ◽  
Transmission Electron ◽  
Non Destructive ◽  
Zone Melt

ABSTRACTMicro Raman spectroscopy (RS) is used to study the crystalline quality and the stresses in the thin superficial silicon layer of Silicon-On-Insulator (SO) materials. Results are presented for SIMOX (Separation by IMplanted OXygen) and ZMR (Zone Melt Recrystallized) substrates. Both as implanted and annealed SIMOX structures are investigated. The results from the as implanted structures are correlated with spectroscopic ellipsometry (SE) and cross-section transmission electron microscopy (TEM) analyses on the same material. Residual stress in ZMR substrates is studied in low- and high temperature gradient regions.

Scanning electron microscopy and micro-Raman spectroscopy of slip layers of Hellenistic ceramic wares from Dorylaion/Turkey

2011 ◽  
Vol 37 (6) ◽  
pp. 1879-1887 ◽  
Author(s):  
Ali İssi ◽  
Aleksandra Raškovska ◽  
Alpagut Kara ◽  
Orhideja Grupce ◽  
Biljana Minčeva-Šukarova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Micro Raman Spectroscopy ◽  
Scanning Electron

Microstructure and growth of joins in melt-textured YBa2Cu3O7−δ

2001 ◽  
Vol 16 (8) ◽  
pp. 2298-2305 ◽  
Author(s):  
A. D. Bradley ◽  
W. Lo ◽  
M. Mironova ◽  
N. H. Babu ◽  
D. A. Cardwell ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Liquid Phase ◽  
Grain Boundary ◽  
Electron Probe ◽  
High Quality ◽  
Strongly Coupled ◽  
External Agent ◽  
Transmission Electron

Joining of melt-textured YBa2Cu3O7-δ (Y123) grains has been achieved without use of an external agent. The technique uses barium-cuprate liquid phase released from platelet boundaries to mediate the growth of Y123 at the interface between two grains. The epitaxial nature and high quality of the growth was determined by optical and transmission electron microscopy. The composition of Ba–Cu–O phases found in some parts of the joins was determined by electron probe microanalysis. A clean low-angle join was found to consist of a grain boundary with dislocation networks and facets. Transport critical current measurements on this type of join revealed strongly coupled behavior. The technique shows promise for the joining of melt-textured material for power engineering applications.

scholarly journals Mineral characterization of soil type ranker formed on serpentines occurring in southern Belgrade environs Bubanj Potok

2012 ◽  
Vol 27 (2) ◽  
pp. 131-136
Author(s):  
Bozidar Cekic ◽  
Valentin Ivanovski ◽  
Aleksandar Djordjevic ◽  
Velimir Aleksic ◽  
Zorica Tomic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Soil Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Detrital Mineral ◽  
Scanning Electron

The paper addresses the issue of health risk associated with the presence of chrysotile in the soil type ranker formed on massive serpentines occurring in the area of Bubanj Potok, a settlement located in the southern Belgrade environs, Serbia. Characterization of the ranker soil was conducted by scanning electron microscopy, X-ray diffraction, micro-Raman spectroscopy and transmission 57Fe M?ssbauer spectroscopy. Scanning electron microscopy figures showed regular shaped smectite (montmorillonite) particles, aggregates of chlorite, and elongated sheets of serpentines minerals antigorite. X-ray diffraction analysis confirmed the presence of detrital mineral quartz polymorph as well as minor amounts of other mineral species. Micro-Raman spectroscopy identified the presence of dominant minerals, such as montmorillonite, kaolinite, muscovite, gypsum, calcite, albite, amphiboles (hornblende/kaersutite) and orthoclase. Important polymorph silica modifications of quartz, olivine (forsterite), pyroxene (enstatite/ferrosilite, diopside/hedenbergite), and serpentine (antigorite/lizardite/chrysotile) were identified.

scholarly journals Combining Micro-Raman Spectroscopy and Scanning Electron Microscopy Mapping: A Stony Meteorite Study

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7585
Author(s):  
Maya Musa ◽  
Riccardo Rossini ◽  
Daniela Di Martino ◽  
Maria Pia Riccardi ◽  
Massimiliano Clemenza ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Combined Approach ◽  
Micro Raman Spectroscopy ◽  
Analytical Protocol ◽  
Non Destructive ◽  
The Universe ◽  
Scanning Electron ◽  
Stony Meteorite

Meteorite characterisation represents a privileged and unique opportunity to increase our knowledge about the materials composing the Universe and, particularly, the Proto Solar System. Moreover, meteorites studies evolve contextually with the development of analytical technologies. In the present paper, the results from an unclassified stony meteorite (chondrite) characterisation have been reported on the basis of the innovative analytical protocol presented here. Advanced Mapping by micro-Raman Spectroscopy and Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy have been combined to disclose molecular and elemental features on the same regions sample at a micrometric resolution. Thanks to their non-destructive properties, the mapping tools of both instruments have been applied to single chondrules analysis and the best match between the mineralogical information and the chemical composition has been obtained. This combined approach proved to be highly suitable in disclosing the crystallinity features of the phases, with in-depth spatial and morphological details too.

scholarly journals Fabrication of Nanofiltration Membrane Utilising Surfactant Via Non-Solvent Induced Phase Separation Method

2019 ◽  
Vol 5 (2) ◽  
pp. 129
Author(s):  
Rosmanisah Mohamat
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Phase Separation ◽  
Membrane Filtration ◽  
Nanofiltration Membrane ◽  
Electrochemical Exfoliation ◽  
Micro Raman Spectroscopy ◽  
Treatment Application ◽  
Scanning Electron

In this work, graphene oxide (GO) and titanium dioxide (TiO2) were used as an additive to fabricate the nanofiltration (NF) membrane. GO was synthesised via electrochemical exfoliation method utilising sodium bis(3,5,5-trimethyl-1-hexyl) sulphosuccinate (AOT4) surfactant. The synthesised GO was then used to fabricate PVDF-based NF membrane namely PVDF/GO_TiO2 via non-solvent induced phase separation (NIPS) method. The effects of embedded GO and TiO2 on the morphology and structural properties of PVDF/GO_TiO2 were investigated by using field emission scanning electron microscopy (FESEM) and micro-Raman spectroscopy. The finding shows that PVDF/GO_TiO2 present thin and dense top layer supported by macro-voids sub-layer with sponge-like layer at the bottom. Based on its morphology, the fabricated PVDF/GO_TiO2 membrane is potential to be applied as membrane filtration for water treatment application.

Micromachined Silicon Grids for Direct TEM Characterization of Carbon Nanotubes Grown by CVD

2006 ◽  
Vol 963 ◽  
Author(s):  
Yongho Choi ◽  
Jason Johnson ◽  
Ryan Moreau ◽  
Eric Perozziello ◽  
Ant Ural
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Chemical Vapor ◽  
Silicon Substrates ◽  
Back Side ◽  
Post Processing ◽  
Tem Analysis ◽  
Micro Raman Spectroscopy

ABSTRACTTransmission electron microscopy (TEM) is a key technique in the structural characterization of carbon nanotubes. For device applications, carbon nanotubes are typically grown by chemical vapor deposition (CVD) on silicon substrates. However, TEM requires very thin samples, which are electron transparent. Therefore, for TEM analysis, CVD grown nanotubes are typically deposited on commercial TEM grids by post-processing. This procedure has two problems: It can damage the nanotubes, and it does not work reliably if the nanotube density is too low. The ability to do TEM directly on as-grown nanotubes lying on the silicon substrate would solve these two problems. In this work, for this purpose, we have fabricated micromachined TEM grids from silicon substrates. In particular, we have wet-etched large membranes from the back side of silicon wafers with a thin layer of thermal oxide on them. We have then etched a large array of long and narrow open slits on these membranes from the top side using a deep silicon etcher. Subsequently, we have grown nanotubes on these micromachined TEM grids by CVD, and characterized the nanotubes by high resolution TEM (HRTEM), micro-Raman spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). Since the nanotubes grown on the micromachined substrates are completely suspended over the width of the open slits, these substrates form a natural TEM grid for direct imaging of CVD-grown nanotubes. Furthermore, the signal from the substrate is significantly reduced during micro-Raman spectroscopy, resulting in a better signal-to-noise ratio. In addition, the silicon membranes are strong enough to support AFM and SEM characterization. As a result, these substrates provide a low cost, mass producible, efficient, and reliable platform for direct TEM, Raman, AFM, and SEM analysis of as-grown nanotubes or other nanomaterials on the same substrate, eliminating the need for any post-processing after CVD growth.

Preparation and characteristics of 90° rotated biepitaxial Fe3O4 thin films

2002 ◽  
Vol 17 (8) ◽  
pp. 1985-1991 ◽  
Author(s):  
Hiroshi Matsuda ◽  
Hiroshi Sakakima ◽  
Hideaki Adachi ◽  
Akihiro Odagawa ◽  
Kentaro Setsune
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Electron Diffraction ◽  
Grain Boundary ◽  
Seed Layer ◽  
Tunneling Magnetoresistance ◽  
X Ray ◽  
Transmission Electron

In-plane 90° rotated biepitaxial Fe3O4 thin films have been successfully prepared onto MgO (110) substrates using a CeO2 seed layer and their microstructure, electric, and magnetic properties were investigated. From the x-ray φ-scan measurements, the in-plane epitaxial relations were determined as 〈110〉Fe3O4//〈110〉MgO and 〈001〉Fe3O4//〈001〉MgO for the no-seeded Fe3O4 layer, and 〈001〉Fe3O4//〈110〉MgO and 〈110〉Fe3O4//〈001〉MgO for the CeO2 (110) seeded Fe3O4 layer. The CeO2 seed layer was found to rotate the upper Fe3O4 lattice at 90° upon normal axis to the layer against the no-seeded Fe3O4. The transmission electron microscopy and electron diffraction analyses revealed that the transition region of the biepitaxial Fe3O4 boundary between CeO2-seeded and no-seeded portions consisted of columnarlike polycrystalline grains. The Fe 3O4 films exhibited single-crystallinelike electric and magnetic properties, however, substantial spin-dependent-tunneling magnetoresistance across the 90° grain boundary was not observed even in the antiparallel situation for each Fe3O4 portion.

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