scholarly journals Дозовая зависимость формирования нанокристаллов в имплантированных гелием слоях кремния

2018 ◽  
Vol 44 (7) ◽  
pp. 39
Author(s):  
А.А. Ломов ◽  
А.В. Мяконьких ◽  
Ю.М. Чесноков ◽  
В.В. Денисов ◽  
А.Н. Кириченко ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Nanocrystals ◽  
Implantation Dose ◽  
X Ray ◽  
Transmission Electron ◽  
Helium Ion ◽  
Nanocrystal Formation ◽  
20 Nm ◽  
First Time

AbstractThe possibility of nanocrystal formation in silicon layers subjected to plasma-immersion helium-ion implantation at an energy of 5 keV has been proved for the first time. The effect of the implantation dose on the microstructure of the layers has been studied by X-ray reflectometry, transmission electron microscopy and Raman scattering. It has been established that the formation of silicon nanocrystals with dimensions of 10–20 nm is accompanied by a pronounced dependence on the ion flux and occurs at a dose of 5 × 10^17 cm^–2 with subsequent annealing at 700–800°C. The excessive dose has been shown to cause the destruction of the upper protective sublayer and the degradation of the optical properties of nanocrystals.

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 of ZnO2 Nanocrystals Produced by Hydrothermal Process

2009 ◽  
Vol 1242 ◽  
Author(s):  
R. Esparza ◽  
A. Aguilar ◽  
A. Escobedo-Morales ◽  
C. Patiño-Carachure ◽  
U. Pal ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Process ◽  
High Resolution Electron Microscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Zinc Peroxide ◽  
20 Nm

ABSTRACTZinc peroxide (ZnO2) nanocrystals were directly produced by hydrothermal process. The nanocrystals were synthesized using zinc acetate as precursor and hydrogen peroxide as oxidant agent. The ZnO2 powders were characterized by X-ray powder diffraction and transmission electron microscopy. The results of transmission electron microscopy indicated that the ZnO2powders consisted of nanocrystals with diameters below to 20 nm and a faceted morphology. High resolution electron microscopy observations have been used in order to the structural characterization. ZnO2 nanocrystals exhibit a well-crystallized structure.

Iron-rich particles and globoids in embryos of seeds from phyla Coniferophyta, Cycadophyta, Gnetophyta, and Ginkgophyta: characteristics of early seed plants

2002 ◽  
Vol 80 (9) ◽  
pp. 954-961 ◽  
Author(s):  
John N. A Lott ◽  
Jessica C Liu ◽  
Kelly A Pennell ◽  
Aude Lesage ◽  
M Marcia West
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Dispersive ◽  
Seed Plants ◽  
Embryo Axis ◽  
X Ray ◽  
Common Features ◽  
Transmission Electron ◽  
Iron Manganese ◽  
First Time

For the first time, iron-rich particles were discovered in embryo-axis tissue from dry seeds of genera in four phyla of seed-producing plants. Iron-rich particles were present in dry seeds of phyla Ginkgophyta (Ginkgo), Cycadophyta (Dioon), Gnetophyta (Ephedra), and within the Coniferophyta, representatives of the families Araucariaceae, Cephalotaxaceae, Cupressaceae, Podocarpaceae, Sciadopityaceae, and Taxaceae. These iron-rich particles were determined by energy dispersive X-ray analysis to be rich in phosphorus and iron, but generally contained considerable potassium, some magnesium, and perhaps calcium, chlorine, manganese, and (or) zinc. Transmission electron microscopy revealed that these particles were often less than 0.33 μm in diameter and were naturally electron dense. These particles differed from the globoids that were present in the same cells. Globoids were rich in phosphorus, potassium, and magnesium, but lacked high levels of iron. Globoids sometimes contained calcium and perhaps traces of iron, manganese, and zinc. Frequently, globoids were more electron-dense and more regularly spherical in shape. Iron-rich particles and globoids are apparently common features in embryos of the early seed plants.Key words: iron-rich particles in seeds, Ginkgophyta, Cycadophyta, Gnetophyta, Coniferophyta, globoids in seeds.

Effect of Nano-Sized Metal Colloids on Color Change of Photosensitive Glass by Using X-Ray Irradiation

2009 ◽  
Vol 620-622 ◽  
pp. 509-512
Author(s):  
Yong Kap Park ◽  
In Churl Cho ◽  
Y. Choi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Color Change ◽  
Spherical Shape ◽  
Metal Colloids ◽  
X Ray ◽  
Photosensitive Glass ◽  
Transmission Electron ◽  
Ag Colloid ◽  
20 Nm

X-ray irradiation was applied to control the size of metal colloids in a silicate glass to make a high precise photosensitive glass containing K2O, Na2O, ZnO BaO, 0.01-0.05wt.% Au metal as sensitizer, <1.2wt.% Sb2O3 and SnO2 as thermal reducer. Colorimetry showed that X-ray irradiation effectively works to make the color of red system. Transmission electron microscopy revealed that the metal colloids were oxided and had uniform and spherical shape of 10-20 nm. Au colloid made various colors like pink after heating at 400°C, red at 500°C and dark-red at 600°C. Ag colloid made them like yellow-green at 400°C, yellow at 500°C and dark-brown, respectively.

Subcellular Elemental Analysis With the Abalytiual Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 74-75
Author(s):  
J.A. Chandler ◽  
C.K. Chou
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Elemental Analysis ◽  
Broad Spectrum ◽  
X Ray ◽  
Transmission Electron ◽  
The World ◽  
First Time ◽  
Water Borne

Water-borne copper-chrome-arsenate preservatives(CCA) are now recognised throughout the world as the most effective broad-spectrum preservatives and are extensively used today for a wider range of purposes than any other preservative type. The mode of action of this preservative against decaying fungi, however, is little known and this paper reports investigations into an understanding of the process of treatment. The combination of transmission electron microscopy and x-ray microanalysis has for the first time allowed an accurate location for analysis of the consistuent elements in this preservative when applied to wood.

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).

Synthesis of VO2(A) Nanostructures by a Hydrothermal Method and their Transition to VO2(M)

2011 ◽  
Vol 295-297 ◽  
pp. 368-372 ◽  
Author(s):  
Ya Lan Zhong ◽  
Yi Fu Zhang ◽  
Xin Liu ◽  
Xing Hai Liu ◽  
Chi Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Hydrothermal Method ◽  
Scanning Calorimetry ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Transmission Electron ◽  
First Time

VO2(A) nanobelts have been synthesized using V2O5, H2O2, ethanol, H2O as the starting materials through a facile hydrothermal method. The as-obtained products were characterized by X-ray powder diffraction (XRD), X-ray photoelecton spectroscopy (XPS), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). Some parameters, such as, the reaction time, reaction temperature and the ratio of EtOH/H2O, have greatly influenced on the phases and morphologies of the final products. It was found that VO2(A) can be converted to VO2(M) at 700 °C for 2 h for the first time. Furthermore, the phase transition properties of VO2(A) and VO2(M) phases were respectively studied.

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