Ion irradiation for controlling composition and structure of metal alloy nanoclusters in SiO2

2004 ◽  
Vol 345-346 ◽  
pp. 685-688 ◽  
Author(s):  
V. Bello ◽  
G. De Marchi ◽  
C. Maurizio ◽  
G. Mattei ◽  
P. Mazzoldi ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Metal Alloy ◽  
Composition And Structure ◽  
Structure Of Metal

scholarly journals Effect of Composition and Structure of Metal Oxide Composites Nanostructured on Their Conductive and Sensory Properties

2021 ◽  
Author(s):  
G. N. Gerasimov ◽  
V. F. Gromov ◽  
M. I. Ikim ◽  
L. I. Trachtenberg
Keyword(s):  
Metal Oxide ◽  
Reaction Products ◽  
Active Particles ◽  
Composition And Structure ◽  
Structure Of Metal ◽  
Catalytically Active ◽  
Reducing Gases ◽  
Oxide Composites ◽  
The Relationship

Abstract The relationship between the structure and properties of nanoscale conductometric sensors based on binary mixtures of metal oxides in the detection of reducing gases in the environment is considered. The sensory effect in such systems is determined by the chemisorption of oxygen molecules and the detected gas on the surface of metal oxide catalytically active particles, the transfer of the reaction products to electron-rich nanoparticles, and subsequent reactions. Particular attention is paid to the doping of nanoparticles of the sensitive layer. In particular, the effect of doping on the concentration of oxygen vacancies, the activity of oxygen centers, and the adsorption properties of nanoparticles is discussed. In addition, the role of heterogeneous contacts is analyzed.

Laws of change in the composition and structure of metal near the welded joint of work pieces for dental drills

1982 ◽  
Vol 16 (5) ◽  
pp. 174-178 ◽  
Author(s):  
G. I. Altareva ◽  
V. I. Bazhykhin ◽  
G. P. Gerasev ◽  
V. M. Matukhnov ◽  
T. O. Shmyreva
Keyword(s):  
Welded Joint ◽  
Composition And Structure ◽  
Structure Of Metal

Effect of the composition and structure of metal oxide nanocomposites on the sensor process when detecting reducing gases

2017 ◽  
Vol 91 (9) ◽  
pp. 1609-1620 ◽  
Author(s):  
G. N. Gerasimov ◽  
V. F. Gromov ◽  
T. V. Belysheva ◽  
M. I. Ikim ◽  
L. I. Trakhtenberg
Keyword(s):  
Metal Oxide ◽  
Composition And Structure ◽  
Structure Of Metal ◽  
Reducing Gases ◽  
Effect Of The Composition

Optimization of Composition and Structure of Metal‐Hydride Electrodes

1994 ◽  
Vol 141 (7) ◽  
pp. 1747-1750 ◽  
Author(s):  
Konstantin Petrov ◽  
Abbas A. Rostami ◽  
Arnaldo Visintin ◽  
Supramaniam Srinivasan
Keyword(s):  
Metal Hydride ◽  
Composition And Structure ◽  
Structure Of Metal ◽  
Metal Hydride Electrodes ◽  
Optimization Of Composition

Gas-phase composition and structure of metal oxide tetrafluorides

1974 ◽  
Vol 13 (10) ◽  
pp. 2366-2370 ◽  
Author(s):  
Robert T. Paine ◽  
Robin S. McDowell
Keyword(s):  
Phase Composition ◽  
Metal Oxide ◽  
Gas Phase ◽  
Composition And Structure ◽  
Structure Of Metal

Effets of surfaces on precipitate morphology in irradiated thin foils

1978 ◽  
Vol 36 (1) ◽  
pp. 654-655
Author(s):  
D.I. Potter ◽  
A. Taylor
Keyword(s):  
Ion Irradiation ◽  
Dark Field Image ◽  
Thin Foil ◽  
Dark Field ◽  
Al Alloy ◽  
Bright Field Image ◽  
Dislocation Loops ◽  
Precipitate Morphology ◽  
Thin Foils

Thermal aging of Ni-12.8 at. % A1 and Ni-12.7 at. % Si produces spatially homogeneous dispersions of cuboidal γ'-Ni3Al or Ni3Si precipitate particles arrayed in the Ni solid solution. We have used 3.5-MeV 58Ni+ ion irradiation to examine the effect of irradiation during precipitation on precipitate morphology and distribution. The nearness of free surfaces produced unusual morphologies in foils thinned prior to irradiation. These thin-foil effects will be important during in-situ investigations of precipitation in the HVEM. The thin foil results can be interpreted in terms of observations from bulk irradiations which are described first.Figure 1a is a dark field image of the γ' precipitate 5000 Å beneath the surface(∿1200 Å short of peak damage) of the Ni-Al alloy irradiated in bulk form. The inhomogeneous spatial distribution of γ' results from the presence of voids and dislocation loops which can be seen in the bright field image of the same area, Fig. 1b.

Crystal Structure Analysis of Cu-Zr Alloys by Convergent Beam Diffraction

1981 ◽  
Vol 39 ◽  
pp. 354-355
Author(s):  
A. F. Marshall ◽  
J. W. Steeds ◽  
D. Bouchet ◽  
S. L. Shinde ◽  
R. G. Walmsley
Keyword(s):  
Crystal Structure ◽  
Point Group ◽  
Intermetallic Phase ◽  
Three Dimensional ◽  
Crystal Structure Analysis ◽  
Ion Milling ◽  
Composition And Structure ◽  
Unit Cells ◽  
Sputter Deposited ◽  
Convergent Beam

Convergent beam electron diffraction is a powerful technique for determining the crystal structure of a material in TEM. In this paper we have applied it to the study of the intermetallic phases in the Cu-rich end of the Cu-Zr system. These phases are highly ordered. Their composition and structure has been previously studied by microprobe and x-ray diffraction with sometimes conflicting results.The crystalline phases were obtained by annealing amorphous sputter-deposited Cu-Zr. Specimens were thinned for TEM by ion milling and observed in a Philips EM 400. Due to the large unit cells involved, a small convergence angle of diffraction was used; however, the three-dimensional lattice and symmetry information of convergent beam microdiffraction patterns is still present. The results are as follows:1) 21 at% Zr in Cu: annealed at 500°C for 5 hours. An intermetallic phase, Cu3.6Zr (21.7% Zr), space group P6/m has been proposed near this composition (2). The major phase of our annealed material was hexagonal with a point group determined as 6/m.

Off-axis electron holography applied to the study of interfaces

1992 ◽  
Vol 50 (1) ◽  
pp. 244-245
Author(s):  
J.K. Weiss ◽  
M. Gajdardziska-Josifovska ◽  
M. R. McCartney ◽  
David J. Smith
Keyword(s):  
Electric Fields ◽  
Resolution Enhancement ◽  
Interfacial Structure ◽  
Atomic Scale ◽  
Bulk Property ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Composition And Structure ◽  
Chemical Segregation ◽  
Diffraction Effects

Interfacial structure is a controlling parameter in the behavior of many materials. Electron microscopy methods are widely used for characterizing such features as interface abruptness and chemical segregation at interfaces. The problem for high resolution microscopy is to establish optimum imaging conditions for extracting this information. We have found that off-axis electron holography can provide useful information for the study of interfaces that is not easily obtained by other techniques.Electron holography permits the recovery of both the amplitude and the phase of the image wave. Recent studies have applied the information obtained from electron holograms to characterizing magnetic and electric fields in materials and also to atomic-scale resolution enhancement. The phase of an electron wave passing through a specimen is shifted by an amount which is proportional to the product of the specimen thickness and the projected electrostatic potential (ignoring magnetic fields and diffraction effects). If atomic-scale variations are ignored, the potential in the specimen is described by the mean inner potential, a bulk property sensitive to both composition and structure. For the study of interfaces, the specimen thickness is assumed to be approximately constant across the interface, so that the phase of the image wave will give a picture of mean inner potential across the interface.

Xenon ion irradiation of superconducting YBa2Cu3O7 thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 92-93
Author(s):  
H. Watanabe ◽  
B. Kabius ◽  
B. Roas ◽  
K. Urban
Keyword(s):  
Defect Formation ◽  
Ion Irradiation ◽  
High Resolution Electron Microscopy ◽  
Structural Disorder ◽  
Flux Lines ◽  
Pinning Effect ◽  
Magnetic Flux Lines ◽  
Resolution Electron ◽  
Radiation Induced ◽  
Induced Defects

Recently it was reported that the critical current density(Jc) of YBa2Cu2O7, in the presence of magnetic field, is enhanced by ion irradiation. The enhancement is thought to be due to the pinning of the magnetic flux lines by radiation-induced defects or by structural disorder. The aim of the present study was to understand the fundamental mechanisms of the defect formation in association with the pinning effect in YBa2Cu3O7 by means of high-resolution electron microscopy(HRTEM).The YBa2Cu3O7 specimens were prepared by laser ablation in an insitu process. During deposition, a substrate temperature and oxygen atmosphere were kept at about 1073 K and 0.4 mbar, respectively. In this way high quality epitaxially films can be obtained with the caxis parallel to the <100 > SrTiO3 substrate normal. The specimens were irradiated at a temperature of 77 K with 173 MeV Xe ions up to a dose of 3.0 × 1016 m−2.

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