scholarly journals Laser irradiation of SiC-MoSi2 composite ceramics

2008 ◽  
Vol 40 (3) ◽  
pp. 271-281
Author(s):  
Marquez Aguilar ◽  
M. Vlasova ◽  
M.C. Reséndiz-González ◽  
M. Kakazey ◽  
Mayorga Cruz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Laser Irradiation ◽  
Irradiation Time ◽  
Composite Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ir Laser ◽  
Mosi2 Composite

The influence of continuous IR laser irradiation (? = 1064 nm, P = 240 mW) on SiC-MoSi2 composite ceramics was investigated by X-ray diffraction, electron microscopy, atomic force microscopy, and X-ray microanalysis. The irradiation of specimens was carried out in air. It was established that, due to heating of the surface under laser irradiation, oxidation of SiC and MoSi2 and sublimation of SiO (SiO2) and MoO3 take place. Depending on the content of the components in the ceramics and the irradiation time, SiO2 or MoO3 layers form on the surface or disappear from it. For a long irradiation time, the oxidation and cleaning of the surface (sublimation of oxides) are cyclic in character.

scholarly journals Laser treatment of SiC-C5Si3 ceramics in N2-O2 medium

2005 ◽  
Vol 37 (3) ◽  
pp. 217-223
Author(s):  
M. Vlasova ◽  
Aguilar Marquez ◽  
M. Kakazey ◽  
T. Tomila ◽  
A. Bykov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ceramic Composite ◽  
Silicon Oxide ◽  
Silicon Oxynitride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ir Laser ◽  
Gas Medium

By methods of X-ray diffraction, electron microscopy, atomic force microscopy and X-ray microanalysis, IR-spectroscopy the influence of IR laser irradiation (1064 nm, 175 W) on a target consisting of a SiC-Cr5Si3 ceramic composite was investigated. Irradiation of samples was carried out in N2+O2 medium at a pressure of 2 at. It was established that the surface temperature is ~ 2000 K. Silicon and silica are evaporated from the surface and during gas medium transit silicon oxide and silicon oxynitride are formed. On the base of ablative products in the zone of precipitation the film was formed.

Lateral Size of Self-Patterned Nanostructures Controlled by Multi-Step Deposition

2005 ◽  
Vol 106 ◽  
pp. 117-122 ◽  
Author(s):  
Izabela Szafraniak ◽  
Dietrich Hesse ◽  
Marin Alexe
Keyword(s):  
Electron Microscopy ◽  
Ultrathin Films ◽  
Lateral Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Non Volatile Memory ◽  
Ferroelectric Capacitors ◽  
Scanning Electron

Self-patterning presents an appealing alternative to lithography for the production of arrays of nanoscale ferroelectric capacitors for use in high density non-volatile memory devices. Recently a self-patterning method, based on the use of the instability of ultrathin films during hightemperature treatments, was used to fabricate nanosized ferroelectrics. This paper reports the use of the method for the preparation of PZT nanoislands on different single crystalline substrates - SrTiO3, MgO and LaAlO3. Moreover, a multi-step deposition procedure in order to control lateral the dimension of the crystals was introduced. The nanostructures obtained were studied by atomic force microscopy, scanning electron microscopy and X-ray diffraction.

Wettability and Nanotribological Response of Silicon Surfaces Functionalized by Ion Implantation

2012 ◽  
Vol 730-732 ◽  
pp. 257-262
Author(s):  
Bruno Nunes ◽  
Sergio Magalhães ◽  
Nuno Franco ◽  
Eduardo Alves ◽  
Ana Paula Serro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ion Implantation ◽  
Silicon Surfaces ◽  
Iron Ions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Electron

Aiming to improve the nanotribological response of Si-based materials we implanted silicon wafers with different fluences of iron ions (up to 2x1017 cm-2). Implantation was followed by annealing treatments at temperatures from 550°C to 1000°C. The implanted surfaces were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and wettability tests. Then, samples were submitted to AFM-based nanowear tests. We observe an increase of both hidrophobicity and and wear resistance of the implanted silicon, indicating that ion implantation of Si can be a route to be deeper explored in what concerns tribomechanical improvement of Si.

(G03 Best Paper Award Winner) Analysis of Sn Behavior During Ni/GeSn Solid-State Reaction by Correlated X-ray Diffraction, Atomic Force Microscopy, and Ex-situ/In-situ Transmission Electron Microscopy

2020 ◽  
Vol MA2020-02 (24) ◽  
pp. 1750-1750
Author(s):  
Andrea Quintero Colmenares ◽  
Patrice Gergaud ◽  
Jean-Michel Hartmann ◽  
Vincent Delaye ◽  
Nicolas Bernier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ex Situ ◽  
Paper Award ◽  
X Ray Diffraction ◽  
Award Winner ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

Grain Size Effect on Lattice of Ni Nanocrystals Prepared Through Polyol Method

2008 ◽  
Vol 8 (8) ◽  
pp. 4127-4131 ◽  
Author(s):  
G. S. Okram ◽  
Kh. Namrata Devi ◽  
H. Sanatombi ◽  
Ajay Soni ◽  
V. Ganesan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
Polyol Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Electron

Nanocrystalline nickel powders were prepared with grain size 'd' in the range 40–100 nm diameters through polyol method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used for characterization. XRD of the prepared samples consistently matched with standard fcc structure of nickel without any impurity peak. Detailed analysis and calculations using Scherrer equation for (111) peak revealed systematic increase in line width and peak shifting towards lower diffraction 2θ angles with decrease in nickel to ethylene glycol mole ratio. Different values of d estimated from various peaks of each sample suggested associated microstrains in the nanograins. Values of d estimated from X-ray diffraction patterns were compared with those obtained from atomic force microscopy and scanning electron microscopy results, and discussed. Observed lattice expansion is explained, on the basis of a theoretical model of linear elasticity.

scholarly journals The Influence of the Preparation and Stability of Nanofluids for Heat Transfer

2019 ◽  
Vol 25 (4) ◽  
pp. 45-54 ◽  
Author(s):  
Noor Sabih Majeed ◽  
Basma A. Abdulmajeed ◽  
Anwar Khudhur Yaseen
Keyword(s):  
Heat Transfer ◽  
Electron Microscopy ◽  
Base Fluid ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Stability ◽  
Scanning Electron

Recently the use of nanofluids represents very important materials. They are used in different branches like medicine, engineering, power, heat transfer, etc. The stability of nanofluids is an important factor to improve the performance of nanofluids with good results. In this research two types of nanoparticles, TiO2 (titanium oxide) and γ-Al2O3 (gamma aluminum oxide) were used with base fluid water. Two-step method were used to prepare the nanofluids. One concentration 0.003 vol. %, the nanoparticles were examined. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-ray diffraction (XRD) were used to accomplish these tests. The stability of the two types of nanofluids is measured by zeta potential and UV-vis spectrophotometer. The results showed that γ-Al2O3/water has more stable than TiO2/ water for the same period of time.  

Fabrication and Characterization of Polyaniline–ZnO Hybrid Nanocomposite Thin Films

2008 ◽  
Vol 8 (4) ◽  
pp. 1757-1761 ◽  
Author(s):  
Ajeet Kaushik ◽  
Jitendra Kumar ◽  
M. K. Tiwari ◽  
R. Khan ◽  
B. D. Malhotra ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nanocomposite Thin Films ◽  
Scanning Electron

Polyaniline (PANI)–ZnO nanocomposite thin film has been successfully fabricated on glass substrates by using vacuum deposition technique. The as-grown PANI–ZnO nanocomposite thin films have been characterized using X-ray diffraction, Scanning Electron Microscopy, Atomic Force Microscopy, UV-visible spectrophotometer and Fourier Transform Infrared (FTIR) spectroscopy, respectively. X-ray diffraction of as-grown film shows the reflection of ZnO nanoparticles along with a broad peak of PANI. The surface morphology of nanocomposite films has been investigated using scanning electron microscopy and atomic force microscopy. The hypsochromic shift of the UV absorption band corresponding to π–π* transition in polymeric chain of PANI and a band at 504 cm –1 due to ZnO nanoparticles has been observed in the FTIR spectra. The hydrogen bonding between the imine group of PANI and ZnO nanoparticle has been confirmed from the presence of the absorbance band at 1151 cm–1 in the FTIR spectra of the nanocomposite thin films.

scholarly journals Ultrashort Pulsed Laser Ablation of Magnesium Diboride: Plasma Characterization and Thin Films Deposition

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Angela De Bonis ◽  
Agostino Galasso ◽  
Antonio Santagata ◽  
Roberto Teghil
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Optical Emission ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Laser Target ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

A MgB2target has been ablated by Nd:glass laser with a pulse duration of 250 fs. The plasma produced by the laser-target interaction, showing two temporal separated emissions, has been characterized by time and space resolved optical emission spectroscopy and ICCD fast imaging. The films, deposited on silicon substrates and formed by the coalescence of particles with nanometric size, have been analyzed by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy, and X-ray diffraction. The first steps of the films growth have been studied by Transmission Electron Microscopy. The films deposition has been studied by varying the substrate temperature from 25 to 500°C and the best results have been obtained at room temperature.

Preparation of Photocatalytic Nanostructured TiO2 Thin Films

2008 ◽  
Vol 587-588 ◽  
pp. 795-799 ◽  
Author(s):  
A. Di Paola ◽  
M. Addamo ◽  
M. Bellardita ◽  
E. García-López ◽  
G. Marcì ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dip Coating ◽  
Coating Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Glass Slides ◽  
Scanning Electron

Photoactive films consisting of pure anatase, brookite or rutile were deposited on glass slides by a dip coating process from water dispersions or solutions obtained by using TiCl4 as the precursor. The films were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy. The photocatalytic activity of the various samples was evaluated by using the photooxidation of 2-propanol in gas solid regime as probe reaction. Brookite and anatase films showed a good photoactivity degrading the substrate and the propanone produced during the reaction.

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