scholarly journals Quartz Crystallite Size and Moganite Content as Indicators of the Mineralogical Maturity of the Carboniferous Chert: The Case of Cherts from Eastern Asturias (Spain)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallite Size ◽  
Archaeological Sites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared And Raman Spectroscopy ◽  
First Time ◽  
Geological Formations

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.

Boron Nitride Nanotubes: Nanoparticles Functionalization and Junction Fabrication

2007 ◽  
Vol 7 (2) ◽  
pp. 530-534 ◽  
Author(s):  
Chunyi Zhi ◽  
Yoshio Bando ◽  
Guozhen Shen ◽  
Chengchun Tang ◽  
Dmitri Golberg
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Boron Nitride ◽  
Boron Nitride Nanotubes ◽  
X Ray Diffraction ◽  
Carbon Nanostructure ◽  
Wet Chemistry ◽  
X Ray ◽  
Transmission Electron ◽  
First Time

Adopting a wet chemistry method, Au and Fe3O4 nanoparticles were functionalized on boron nitride nanotubes (BNNTs) successfully for the first time. X-ray diffraction pattern and transmission electron microscopy were used to characterize the resultant products. Subsequently, a method was proposed to fabricate heterojunction structures based on the particle-functionalized BNNTs. As a demonstration, BNNT-carbon nanostructure, BNNT-ZnO and BNNT-Ga2O3 junctions were successfully fabricated using the functionalized particles as catalysts.

Fabrication of boron carbonitride (BCN) nanotubes and giant fullerene cages

2010 ◽  
Vol 88 (12) ◽  
pp. 1256-1261 ◽  
Author(s):  
Guifang Sun ◽  
Faming Gao ◽  
Li Hou
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
The Novel ◽  
X Ray Diffraction ◽  
Boron Carbonitride ◽  
X Ray ◽  
Transmission Electron ◽  
New Form ◽  
First Time ◽  
Electron Energy Loss

Boron carbonitride (BCN) nanotubes have been successfully prepared using NH4Cl, KBH4, and ZnBr2 as the reactants at 480 °C for 12 h by a new benzene-thermal approach in a N2 atmosphere. As its by-product, a new form of carbon regular hexagonal nanocages are observed. The samples are characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), transmission electron diffraction (TED), electron energy loss spectroscopy (EELS), and high-resolution transmission electron microscopy (HRTEM). The prepared nanotubes have uniform outer diameters in the range of 150 to 500 nm and a length of up to several micrometerss. The novel carbon hexagonal nanocages have a typical size ranging from 100 nm to 1.5 µm, which could be the giant fullerene cages of [Formula: see text] (N = 17∼148). So, high fullerenes are observed for the first time. The influences of reaction temperature and ZnBr2 on products and the formation mechanism of BCN nanotubes are discussed.

Synthesis and characterization of 3D Cu0.45Mn0.55O2 nanoflowers with novel photoluminescence and magnetic properties

2014 ◽  
Vol 28 (09) ◽  
pp. 1450071
Author(s):  
Arbab Mohammad Toufiq ◽  
Fengping Wang ◽  
Qurat-ul-ain Javed ◽  
Quanshui Li ◽  
Yan Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Growth Method ◽  
First Time

In this paper, three-dimensional (3D) Cu 0.45 Mn 0.55 O 2 nanoflowers self-assembled by interconnecting dense stacked single-crystalline nanoplates have been prepared using the template-free hydrothermal growth method. The morphology, phase structure and composition of the as-prepared nanomaterial were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) with selected area electron diffraction (SAED) and energy-dispersive X-ray spectroscopy (EDX). FESEM and TEM analyses show that the size of 3D Cu 0.45 Mn 0.55 O 2 nanoflowers is in the range of 1–1.5 μm and the thickness of interconnected nanoplates is about 40 nm on the average. The photoluminescence (PL) spectra of the as-prepared Cu 0.45 Mn 0.55 O 2 nanostructures at room temperature exhibits prominent emission bands located in red–violet spectral region. Moreover, magnetic investigations revealed the weak ferromagnetic behavior of the as-prepared Cu 0.45 Mn 0.55 O 2 nanoflowers and reported for the first time using vibrating sample magnetometer (VSM).

scholarly journals Direct Fabrication of Cobalt Oxide Nanoparticles Employing Sucrose as a Combustion Fuel

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
M. Th. Makhlouf ◽  
B. M. Abu-Zied ◽  
T. H. Mansoure
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallite Size ◽  
Thermal Analyses ◽  
Combustion Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cobalt Oxide Nanoparticles ◽  
Transmission Electron

Combustion method has been used as a fast and facile method to prepare nanocrystalline Co3O4 spinel employing sucrose as a combustion fuel. The products were characterized by thermal analyses (TGA and DTA), X-ray diffraction technique (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. Experimental results revealed that the molar ratio of fuel/oxidizer (F/O) plays an important role in controlling the crystallite size of Co3O4 nanoparticles. Transmission electron microscopy indicated that the crystallite size of Co3O4 nanocrystals was in the range of 13–32 nm. X-ray diffraction confirmed the formation of CoO phase with spinel Co3O4. The effect of calcination temperature on crystallite size and morphology has been, also, discussed.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Multi-scale Investigation of Heterogeneous Swift Heavy Ion Tracks in Stannate Pyrochlore

2021 ◽  
Author(s):  
Eric O'Quinn ◽  
Cameron Tracy ◽  
William F. Cureton ◽  
Ritesh Sachan ◽  
Joerg C. Neuefeind ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heavy Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Modifications ◽  
Multi Scale ◽  
Ion Tracks ◽  
Swift Heavy Ion ◽  
Transmission Electron

Er2Sn2O7 pyrochlore was irradiated with swift heavy Au ions (2.2 GeV), and the induced structural modifications were systematically examined using complementary characterization techniques including transmission electron microscopy (TEM), X-ray diffraction...

Detonation Synthesis of Nano-Size Materials

1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleation And Growth ◽  
Detonation Synthesis ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Size

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.

Hydrothermal Synthesis and Characterization of BiFeO3 Polyhedral Crystallites

2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.

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