Download or read book Resolution of Lattice Defects in Metals by Positron Annihilation written by and published by . This book was released on 1981 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Lattice Defects on Positron Annihilation in Metals written by Barry T. A. McKee and published by . This book was released on 1967 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Radiation Induced Lattice Defects by Means of Positron Annihilation Spectroscopy written by Riley Craig Ferguson and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Positrons provide a non-destructive technique for probing the nature and size of defects in materials with atomic-scale sensitivity. This work will focus on the powerful capabilities of positron annihilation spectroscopy (PAS) to study the evolution of defects and defect structures. This invaluable tool can aid in developing and characterizing advanced materials, with diverse applications such as nuclear reactors, optoelectronics, nanotechnology, polymers, medical sciences, and more. The work presented in this thesis aims to gain a fundamental understanding of the formation and evolution of defect structures of various metals and alloys under irradiation by applying the techniques and concepts of PAS. Various other characterization techniques are also utilized simultaneously to interpret the positron data better and further enhance our understanding of these materials. Depth-resolved PAS was used to identify vacancy clusters and measure their density as a function of depth in three samples (HfMoTiVZr, HfNbTiZr, and HfNbTaTiZr bulk alloys), performed at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) in Dresden, Germany. The samples were studied before and after irradiation from 10 MeV Si ions. The behavior of these alloys under irradiation is discussed and quantified in this work. A single branch of samples from the multi-principal element alloy (MPEA) HfNbTaTiZr (Nb, HfNb, HfNbZr, HfNbTiZr, HfNbTaTiZr) was synthesized into thin films on MgO substrate at the Center of Integrated Nanotechnologies (CINT) at the Los Alamos National Laboratory (LANL), to study the role of chemical complexity in an alloy's response to irradiation. There are four sets of these MPEA-based thin film samples, where one will be kept as a reference, and one will be studied with in situ PAS (iPAS), and two sets will be studied with ex situ PAS. The synthesis of these MPEA-based thin films and the design of the PAS experiment for each set is described in this work, along with other characterization techniques used together with this work. This work was made possible through the support of the National Science Foundation (NSF) under grant number DMR-2005064 and by the Fundamental Understanding of Transport Under Reactor Extremes (FUTURE), an Energy Frontier Research Center funded by the DOE, Office of Science, Basic Energy Sciences.

Download or read book Positron annihilation Spectroscopy of Defects in Metals written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Positron annihilation spectroscopy (PAS) has made significant contributions to our knowledge regarding lattice defects in metals in two areas: (i) the determination of atomic defect properties, particularly those of monovacancies, and (ii) the monitoring and characterization of vacancy-like microstructure development during post-irradiation of post-quench annealing. The application of PAS to the study of defects in metals is selectively reviewed and critically assessed within the context of other available techniques for such investigations. Possibilities for using the positron as a localized probe of the structure of atomic defects are discussed. Finally, the present status and future potential of PAS as a tool for the study of defects in metals are considered relative to other available techniques. 92 references, 20 figures.

Download or read book Positron Annihilation in Semiconductors written by Reinhard Krause-Rehberg and published by Springer. This book was released on 1999-01-15 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive book reports on recent investigations of lattice imperfections in semiconductors by means of positron annihilation. It reviews positron techniques, and describes the application of these techniques to various kinds of defects, such as vacancies, impurity vacancy complexes and dislocations.

Download or read book Positrons in Solids written by P. Hautojärvi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: In condensed matter initially fast positrons annihilate after having reached equi librium with the surroundings. The interaction of positrons with matter is governed by the laws of ordinary quantum mechanics. Field theory and antiparticle properties enter only in the annihilation process leading to the emergence of energetic photons. The monitoring of annihilation radiation by nuclear spectroscopic methods provides valuable information on the electron-positron system which can directly be related to the electronic structure of the medium. Since the positron is a positive electron its behavior in matter is especially interesting to solid-state and atomic physi cists. The small mass quarantees that the positron is really a quantum mechanical particle and completely different from any other particles and atoms. Positron physics started about 25 years ago but discoveries of new features in its interac tion with matter have maintained continuous interest and increasing activity in the field. Nowadays it is becoming part of the "stock-in-trade" of experimental physics.

Download or read book Positron Annihilation in Pure Metals and Dilute Binary Alloys in Presence of Lattice Vacancies and the High Resolution Angular Correlation Machine written by and published by . This book was released on 1973 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Positron Annihilation in Perfect and Imperfect Metals written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The current renaissance of investigations of positron annihilation in solids has its origins in the observation that positrons interact strongly with certain crystal-lattice defects. Three properties of the annihilation process are being measured to gain information about the defects or about the local environment of the positron at the instant of its annihilation: positron lifetime, angular correlation of the two annihilation quanta, and Doppler broadening of the 511-keV annihilation line. Until the physics of positron behavior in solids is fully understood, the phenomenon will continue to be useful in a manner analogous to electrical resistivity recovery for identifying the recovery stages in irradiated metals. Ultimately, it is destined to provide detailed quantitative information such as the formation volume of vacancies, vacancy-impurity binding energies and electron momentum distributions and densities at defect sites. 2 tables, 52 refs. (auth).

Download or read book Resolvability of Defect Ensembles with Positron Annihilation Studies written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in the use of positron annihilation to study defect ensembles in and on the surfaces of metals, are pointing the way towards studies where particular positron-electron annihilation modes may be identified and studied in the presence of one another. Although a great deal is understood about the annihilation of positrons in ostensibly defect-free metals, much less is understood when the positron annihilates in complex defect systems such as liquid metals, amorphous solids, or at or near the vacuum-solid interface. In this paper the results of three experiments, all of which demonstrate means by which we can resolve various poistron annihilation channels from one another, are discussed.

Download or read book Defect Characterization with Positron Annihilation Review written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Positron annihilation in metal crystals is reviewed. A brief introduction to the positron annihilation technique is presented first. Then the ability of the positron technique to perform microstructural characterization of four types of lattice defects (vacancies, voids, dislocations, grain boundaries) is discussed. It is frequently not possible to obtain samples that contain only one type of defect in nonnegligible concentrations. Such situations exist for some alloys and for fatigued metal samples. Finally, the current limitations and some future prospects of the technique are presented. 79 references, 14 figures, 1 table. (RWR).

Download or read book Positron Annihilation in Semiconductors written by Reinhard Krause-Rehberg and published by Springer Science & Business Media. This book was released on 1999 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive book reports on recent investigations of lattice imperfections in semiconductors by means of positron annihilation. It reviews positron techniques, and describes the application of these techniques to various kinds of defects, such as vacancies, impurity vacancy complexes and dislocations.

Download or read book Positron Studies of Solids Surfaces and Atoms written by Allen P. Mills and published by . This book was released on 1986 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Defect studies in metals using positron annihilation written by Thomas Maxwell Hall and published by . This book was released on 1974 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Positron Annihilation written by Paul G. Coleman and published by North Holland. This book was released on 1982 with total page 1022 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Defects and Diffusion in Metals XIII written by David J. Fisher and published by Trans Tech Publications Ltd. This book was released on 2011-10-27 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thirteenth volume in the series covers the latest results in the field. As well as some 360 metals-related abstracts, the issue includes original papers on all of the major material groups: “Bulk Diffusion of Homovalent Non-Magnetic Atomic Probes of Titanium and Zirconium in Tungsten Single Crystals”, “Comparative Mössbauer Analysis of Superfine Structure of Hadfield Steel Upon Different Kinds of Severe Deformation”, “Assessment of Microstructural Degradation in 2.25Cr-1Mo Steel ...”, “Isochronal and Isothermal Annealing of Wrought Aluminum Alloy”, “Application of the Photoacoustic Method for the Determination of the Thermal Properties of Heat-Treated and Annealed Al-Li Alloy“, “Effect of Ageing on Microstructures, Electrical Properties and PALS of Aircraft Al Alloy 2024”, “Preparation of C/Cu Composite Powders by High-Energy Ball-Milling”, “Quantitative Analysis of Fiber Fracture in Powder Injection Molded Metal Composites”, “Wear Mechanisms of Ceramic-Reinforced Metal-Matrix Composite ...”, “Development and Characterization of Alumina-Silica Sand Nanoparticle Composites”, “Characterization and Properties of Copper-Silica Sand Nanoparticle Composites”, “Diffusion Processes Affecting the Performance of Heterogeneous Catalysts”, “Analytical Solutions for Moving Elliptical Paraboloid Heat Source in Semi-Infinite Plate”, “Solution for Modeling 3D Moving Heat Sources in a Semi-Infinite Medium ...”, “Probing the Phase Transition in Nanocrystalline TiO2 Powders ...”, “BSCCO 2212 Defective Tellurium Ions on Bi-Site”, “Self-Diffusion in Nano Zinc Sulphide”, “SIMS Study of 30keV H+ Ion-Implanted n-GaAs“, “Optical Studies of Physically Deposited Nano-Ag2Te Thin Films”

Download or read book Positron Spectroscopy of Solids written by Alfredo Dupasquier and published by IOS Press. This book was released on 1995 with total page 830 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lifetime of a positron inside a solid is normally less than a fraction of nanosecond. This is a very short time on a human scale, but is long enough to enable the positron to visit an extended region of the material, and to sense the atomic and electronic structure of the environment. Thus, we can inject a positron in a sample to draw from it some signal giving us information on the microscopic properties of the material. This idea has been successfully developed in a number of positron-based techniques of physical analysis, with resolution in energy, momentum, or position. The complex of these techniques is what we call now positron spectroscopy of solids. The field of application of the positron spectroscopy extends from advanced problems of solid-state physics to industrial applications in the area of characterization of high-tech materials. This volume focuses the attention on the physics that can be learned from positron-based methods, but also frames those methods in a wider context including other experimental approaches. It can be considered as a textbook on positron spectroscopy of solids, the sort of book that the newcomer takes for his approach to this field, but also as a useful research tool for the expert.

Download or read book Positron Annihilation written by A.T. Steward and published by Elsevier. This book was released on 2012-12-02 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: Positron Annihilation focuses on the process of positron annihilation in different environments. Partitioned into two parts with 42 chapters, the book contains the contributions of authors who have done research on the annihilation of positrons, which brought about valuable information on the properties of matter. The first part of the book deals with lengthy review articles, including a survey of the physics of positron annihilation; positron annihilation in metals and the theory involved in the process; and positron annihilation in alkali halides and ionic crystals. Positronium formation and interaction in gases, molecular substances, and ionic crystals are also given attention. Gaseous positronics and positron annihilation in condensed gases and liquids are also discussed. The second part of the book focuses on developments on positron annihilation and the direction of research on this field. The studies concentrate on positron annihilation in various crystals, metals, mercury, liquefied gases, helium, and metal oxides. Numerical representations and analyses are presented to support the processes involved. The book can best serve the interest of those who want to explore further the annihilation of positrons.