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.

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.

This book provides a comprehensive and up-to-date account of the field of low energy positrons and positronium within atomic and molecular physics. Each chapter contains a blend of theory and experiment, giving a balanced treatment of all the topics. Useful for graduate students and researchers in physics and chemistry.

This book provides a coherent and comprehensive overview of the generation and application of mono-energetic positron beams. It has been written by acknowledged experts, at a level accessible to graduate students working, or planning to work, with positron beams, and to scientists in other areas who want to know something about the field.The book begins with a brief historical introduction and an overview of how positron beams are generated and transported. A description of the fate of slow positrons in gaseous and condensed matter, with reference to many of the fundamental measurements made possible by the advent of positron beams, is followed by a discussion on applications in the study of solid surfaces, defect profiling in subsurface regions, interfaces and thin films, and the probing of bulk properties in novel ways. The book ends with a look at the future, considering the prospects for intense positron beams and their potential for further research.

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.

All materials have voids in them, at some scale. Sometimes the voids are ignored, sometimes they are taken into account, and other times they are the focal point of the research. Voids in Materials: From Unavoidable Defects to Designed Cellular Materials takes due notice of all these occurrences, whether designed or unavoidable defects. We define, categorize, and characterize the voids (or empty spaces in materials) and we analyze the effects they have on material properties. This second edition is an updated and expanded central reference for voids in materials and covers all types of voids, intrinsic and intentional, and stochastic and nonstochastic, and the processes and conditions that are needed to create them and is a valuable resource to students in the areas of mechanical engineering, chemical engineering, materials science and engineering, physics, and chemistry, as well as scientists, researchers, and engineers in industry. - the effect of voids in materials; from low volume fraction defects and free volume in polymer networks to high void volume fraction foams and aerogels - how and why voids are introduced into materials across the length scales - biomaterial design used in vivo for soft, hard, and nerve tissue scaffolds - metallic and geopolymeric foams - additive manufacturing technologies used to tailor regularity (R) in the cell structure - stochastic, nonstochastic, and Voronoi foams - the latest techniques for characterizing voids - new chapters, covering the Kirkendall effect to create hollow and porous structures, and nanometer scale voids: nanotubes, zeolites, organic frameworks, and nanoporous noble metals

Selected Papers from Proceeding of the 39th Polish Seminar on Positron Annihilation (PSPA-10), 20-25 June 2010, Kazimierz Dolny, Poland