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Mostrando ítems 1-10 de 17
Artículo
In situ mechanical, temperature and gas exposure treatments of materials combined with variable energy positron beam techniques
(ScienceDirect, 2002-06-21)
An overview is given of the extension of the Delft variable energy positron (VEP) beam facility with equipment for in situ heating, cooling, 4-point bending, hydrogen permeation and gas ad- and absorption of bulk materials, ...
Artículo
A description of bubble growth and gas release during thermal annealing of helium implanted copper
(ScienceDirect, 2004-04)
This paper describes an investigation into the migration and coalescence of equilibrium bubbles in helium implanted copper. Using computer simulation methods, the results indicate that when the swelling averaged over the ...
Artículo
Interface detection in poly-ethylene terephthalate–metal laminates using variable energy positron annihilation
(ScienceDirect, 2005-05-01)
Thin coatings of poly-ethylene terephthalate (PET) on metal (“laminates”) have been studied with a variable energy positron annihilation technique. A correlation between PET crystallinity and the positron annihilation ...
Artículo
Positron beam analysis of structurally ordered porosity in mesoporous silica thin films
(ScienceDirect, 2003-09-15)
Positron beam techniques have been employed to characterise low-k dielectric silica based films, which have two or three dimensional structures of nanometre size pores. Pore fractions vary from 5 to 50%. Positrons implanted ...
Artículo
Adhesion behaviour of CrNx coatings on pre-treated metal substrates studied in situ by PBA and ESEM after annealing
(ScienceDirect, 2005-09-01)
In this paper we present the first combined Positron Beam Analysis (PBA) and Environmental Scanning Electron Microscopy (ESEM) adhesion study on thin chromium nitride (CrNx) coatings. Both techniques are combined with a ...
Artículo
Nano-porosity in silica reinforced methyltrimethoxysilane coatings studied by positron beam analysis
(ScienceDirect, 2003-06)
The porosity in particle reinforced sol-gel coatings has been studied. Silica particles (Ludox-TM40) are introduced into methyl silicate coatings to increase the hardness, the elastic modulus and the fracture toughness. ...
Artículo
Systematic positron study of hydrophilicity of the internal pore surface in ordered low-k silica thin films
(ScienceDirect, 2003-09-15)
Non-destructive Doppler Broadening (DB), Positronium fraction (f-Ps) and Two Dimensional Angular Correlation of Annihilation Radiation (2D-ACAR), Positron Beam Analysis (PBA) techniques have been used to study well-ordered ...
Artículo
Positronium formation in NaY-zeolites studied by lifetime, positron beam Doppler broadening and 3-gamma detection techniques
(ScienceDirect, 2000-06)
Results of positron annihilation measurements on NaY pressed powders and deposited thin films using slow positron beam and conventional fast positron techniques are presented. In lifetime experiments using an external 22Na ...
Artículo
Structural effects due to the incorporation of Ar atoms in the lattice of ZrO2 thin films prepared by ion beam assisted deposition
(ScienceDirect, 2002-09)
Two sets of ZrO2 thin films have been prepared at room temperature by ion beam induced chemical vapour deposition and subsequently annealed up to 1323 K. The two sets of samples have been prepared by using either O2+ or ...
Artículo
Depth-selective 2D-ACAR studies on low-k dielectric thin films
(ScienceDirect, 2003)
Depth-selective 2D-ACAR investigations on ordered mesoporous silica thin films provide direct evidence that para-positronium (p-Ps) created deep in the films can escape through a network of interconnected pores. The depth ...