scholarly journals The Preparation and Characterization ofβ-SiAlON Nanostructure Whiskers

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Pengli Dong ◽  
Xidong Wang ◽  
Mei Zhang ◽  
Min Guo ◽  
Seshadri Seetharaman
Keyword(s):  
Electron Microscope ◽  
Diameter Distribution ◽  
Growth Mechanisms ◽  
X Ray Diffraction ◽  
Vapor Liquid Solid ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Electron ◽  
High Resolution Electron Microscope ◽  
Sintering Method

Two kinds ofβ-SiAlON nanostructure whiskers, rod-like and wool-like whiskers, were synthesized by pressure-less sintering method at 1773 K for 5 hours. The whiskers synthesized were characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and high-resolution electron microscope (HREM) techniques. It was found that diameter distribution of rod-like whiskers was about 80–250 nm, while it was about 45–55 nm in diameter for the wool-like whiskers. The growth mechanisms ofβ-SiAlON nanostructure whiskers are discussed by the vapor-solid (VS) and vapor-liquid-solid (VLS) mechanisms, respectively.

Growth of Single-Phase 2H-SiC Layers by Vapor–Liquid–Solid Process

2010 ◽  
Vol 645-648 ◽  
pp. 45-48 ◽  
Author(s):  
Mamoru Imade ◽  
Shin Takeuchi ◽  
Masahiro Uemura ◽  
Masashi Yoshimura ◽  
Yasuo Kitaoka ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Carbon Source ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Vapor Liquid Solid ◽  
X Ray ◽  
Transmission Electron ◽  
Vls Growth ◽  
Sic Film ◽  
Vapor Liquid

We attempted the vapor–liquid–solid (VLS) growth of SiC film in Si-Li solution using gaseous CH4 as a carbon source at 900 oC. A 100-m-thick liquid-phase epitaxy (LPE) layer was obtained on a 4H-SiC (0001) substrate under CH4 pressure of 0.9 MPa. X-ray diffraction (XRD) and a high-resolution transmission electron microscope (HR-TEM) measurement showed that the LPE layer was single-phase 2H-SiC. We concluded that VLS growth in Si-Li solution using gaseous CH4 as a carbon source is useful for growing single-phase 2H-SiC.

Identification of T1 phase in Al-Li-Cu alloy (2090)

1992 ◽  
Vol 50 (1) ◽  
pp. 188-189
Author(s):  
J.S. Kim ◽  
S. S. Baek ◽  
G. H. Kim ◽  
C. H. Chun
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Zone Axis ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Alloy ◽  
Resolution Electron ◽  
High Resolution Electron Microscope ◽  
Optical Laser

In Al-Li-Cu alloy(2090) the extra spots in the Selected Area Diffraction Pattern (SADP) of [112]α zone axis have been argued. Huang and Ardell described that the extra spots were originated from T1 variants tilted to electron beam. Rioja and Ludwiczak, however, presented that die precursor of T1 termed T1' was present in alloy(2090) and generated the extra spots. Rioja and Ludwiczak explained die existence of extra spots as making the simulated SADP diagrams and analyzing x ray diffraction lines of T1'. The existence of T1' has been inconsistent with the other papers. Huang and Ardell's model has been well recognized in present. The investigations on the extra spots had mainly been restricted in [112]α SADP. In the present paper, the extra spots from [110]αand [100]α zone axes were investigated using High Resolution Electron Microscope (HREM) and optical laser diffractometer.

300kv high-performance analytical TEM (H-9000)

1987 ◽  
Vol 45 ◽  
pp. 108-109
Author(s):  
H. Kobayashi ◽  
H. Sato ◽  
K. Miyauchi ◽  
T. Onai ◽  
K. Shii ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
High Performance ◽  
Image Resolution ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Analytical Microscopy ◽  
High Resolution Electron Microscope

Higher voltage operation has many advantages for transmission electron microscopy.These advantages include better TEM image resolution and ease of specimen imaging. For analytical microscopy, the higher voltage operation has advantages such as higher source brightness, and better spatial resolution.We reported development of a 300kV ultra high resolution electron microscope. At this time, we would like to report an analytical type 300kV electron microscope.We have incorporated a side entry specimen stage which permits ±45° specimen tilt and is convenient for characteristic x-ray detection. We have also incorporated an analytical objective polepiece which has Cs of 2. 5mm, Cc of 2. 3mm and theoretical TEM image resolution of 0.23nm.

Crystal Structures Of L-Nb205 AND L-Ta205

1977 ◽  
Vol 35 ◽  
pp. 188-189
Author(s):  
Sumio Iijima
Keyword(s):  
Electron Microscope ◽  
Complex Nature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resolution Electron ◽  
Unit Cells ◽  
System 2 ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns ◽  
Phase Relationships

Although structures of tantalum pentoxides have been extensively studied, they have not been fully understood because of the complex nature of their X-ray diffraction patterns. In this study we made some observations on crystals of L-Ta2O5 and L-Nb2O5 using a high resolution electron microscope. The latter structure has been believed to be isostructural with L-Ta2O5. The samples were prepared by Dr. Roth at NBS and were parts of the products used for determining phase relationships in niobium pentoxides (1) and the Ta2O5-Ta2WO8 system (2).According to the X-ray data both structures have orthorhombic unit cells with a = 6.2, b = 29.3, c = 3.9Å. The structures are based on the U03-type and the b spacings are nearly 8 times those of the subcell. Electron diffraction (E.D.) patterns of L-Nb2O5 and L-Ta3O5 crystals showing a*-b* reciprocal sections confirmed generally the results of X-ray works (Figs, la and lc).

Luminescent Properties of Gd2MoO6:Eu3+ Nanophosphor for WLEDs

2021 ◽  
Author(s):  
Yan Chen ◽  
Yuemei Lan ◽  
Dong Wang ◽  
Guoxing Zhang ◽  
Wenlong Peng ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Fluorescence Spectra ◽  
Solvothermal Method ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

A series of Gd2-xMoO6:xEu3+(x=0.18-0.38) nanophosphors were synthesized by the solvothermal method. The properties of this nanophosphor were characterized by x-ray diffraction (XRD), transmission electron microscope (TEM), fluorescence spectra and diffuse...

Formation of Graphite Encapsulated Nickel Nanoparticles by Ball Milling and Annealing of Expanded Graphite with Nickel

2011 ◽  
Vol 80-81 ◽  
pp. 217-220 ◽  
Author(s):  
Xue Qing Yue ◽  
Hai Jun Fu ◽  
Da Jun Li
Keyword(s):  
Electron Microscope ◽  
Ball Milling ◽  
Transmission Electron Microscope ◽  
Nickel Nanoparticles ◽  
Size Range ◽  
Expanded Graphite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Powders ◽  
Transmission Electron

Graphite encapsulated nickel nanoparticles were prepared by ball milling andsubsequently annealing a mixture of expanded graphite with nickel powders. The products were characterized by transmission electron microscope and X-ray diffraction. The formation mechanism of the products was discussed. Results show that the products have a size range of 20-150 nm. The graphite and nickel in the products all exhibit a high crystallinity.

Solvothermal Synthesis of Bi2Se3 Hexagonal Nanosheet Crystals

2011 ◽  
Vol 236-238 ◽  
pp. 1712-1716 ◽  
Author(s):  
Hai Tao Liu ◽  
Jun Dai ◽  
Jia Jia Zhang ◽  
Wei Dong Xiang
Keyword(s):  
Electron Microscope ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Scanning Electron

Bismuth selenide (Bi2Se3) hexagonal nanosheet crystals with uniform size were successfully prepared via a solvothermal method at 160°C for 22 h using bismuth trichloride(BiCl3) and selenium powder(Se) as raw materials, sodium bisulfite(NaHSO3) as a reducing agent, diethylene glycol(DEG) as solvent, and ammonia as pH regulator. Various techniques such as X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) were used to characterize the obtained products. Results show that the as-synthesized samples are pure Bi2Se3 hexagonal nanosheet crystals. A possible growth mechanism for Bi2Se3 hexagonal nanosheet crystals is also discussed based on the experiment.

Template Induced Synthesis of Nano-Hydroxyapatite by Co-Precipitation Method

2011 ◽  
Vol 311-313 ◽  
pp. 1713-1716 ◽  
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Chang An Wang ◽  
Li Guo Ma ◽  
Feng Liu
Keyword(s):  
Electron Microscope ◽  
Chondroitin Sulfate ◽  
Aspartic Acid ◽  
Transmission Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Co Precipitation

Nano-hydroxyapatite with different morphology was synthesized by the co-precipitation method coupled with biomineralization using Ca(NO3)2•4H2O and (NH4)2HPO4 as reagents, adding chondroitin sulfate, agarose and aspartic acid as template. The structure and morphology of the prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM).

scholarly journals Effect of Preheating Temperature on Synthesis of Pure BiFeO3 via Sol–Gel Method

Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Pure Bifeo3 ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Preheating Temperature

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.

PHYSICAL PROPERTIES AND MICROSTRUCTURE PERFORMANCE OF LASER ALLOYING Zn MODIFIED AMORPHOUS-NANOCRYSTALS REINFORCED COATING

NANO ◽  
2013 ◽  
Vol 08 (04) ◽  
pp. 1350038 ◽  
Author(s):  
JIANQUAN LI ◽  
HUASHI LIU ◽  
JIANING LI ◽  
GUOZHONG LI
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Electron Microscope ◽  
Crystallization Process ◽  
Laser Alloying ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Transmission Electron ◽  
Improve Wear Resistance

Zn was firstly used to improve wear resistance of a TA7 (Ti–5Al–2.5Sn) titanium alloy surface by mean of a laser alloying (LA) technique. The synthesis of the hard coating on a TA7 titanium alloy by LA of Co–Ti–Cr–TiB2–Zn–CeO2 pre-placed powders was investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). Experimental results indicated lot of the nanocrystals, such as Ti–B/CoZn13 and the amorphous phases were produced in such LA coating. The nucleation and growth of the amorphous phases were retarded by the nanocrystals in a certain extent during the crystallization process of the amorphous phases. Compared with a TA7 alloy substrate, an improvement of the wear resistance was obtained for such LA composite coating.

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