Various experimental techniques for point contact production are described. Examples of point-contact spectra are presented for pure metals, alloys and compounds, as well as for semimetals and semiconductors, heavy fermion systems, Kond-lattices, mixed valence compounds and more. Superconducting point contacts are considered in respect to Andreev reflection and Josephson effects. Special attention is paid to contact conductance fluctuation, and new trends of research are outlined.

The characteristics of electrical contacts have long attracted the attention of researchers since these contacts are used in every electrical and electronic device. Earlier studies generally considered electrical contacts of large dimensions, having regions of current concentration with diameters substantially larger than the characteristic dimensions of the material: the interatomic distance, the mean free path for electrons, the coherence length in the superconducting state, etc. [110]. The development of microelectronics presented to scientists and engineers the task of studying the characteristics of electrical contacts with ultra-small dimensions. Characteristics of point contacts such as mechanical stability under continuous current loads, the magnitudes of electrical fluctuations, inherent sensitivity in radio devices and nonlinear characteristics in connection with electromagnetic radiation can not be understood and altered in the required way without knowledge of the physical processes occurring in contacts. Until recently it was thought that the electrical conductivity of contacts with direct conductance (without tunneling or semiconducting barriers) obeyed Ohm's law. Nonlinearities of the current-voltage characteristics were explained by joule heating of the metal in the region of the contact. However, studies of the current-voltage characteristics of metallic point contacts at low (liquid helium) temperatures [142] showed that heating effects were negligible in many cases and the nonlinear characteristics under these conditions were observed to take the form of the energy dependent probability of inelastic electron scattering, induced by various mechanisms.

The investigation and manipulation of matter on the atomic scale have been revolutionised by scanning tunnelling microscopy and related scanning probe techniques. This book is the first to provide a clear and comprehensive introduction to this subject. Beginning with the theoretical background of scanning tunnelling microscopy, the design and instrumentation of practical STM and associated systems are described in detail, as are the applications of these techniques in fields such as condensed matter physics, chemistry, biology, and nanotechnology. Containing 350 illustrations, and over 1200 references, this unique book represents an ideal introduction to the subject for final-year undergraduates in physics or materials science. It will also be invaluable to graduate students and researchers in any branch of science where scanning probe techniques are used.

Over the last decade, techniques for materials preparation and processing at nanometer scale have advanced rapidly, leading to the introduction of novel principles for a new generation of sensors and detectors. At the same time, the chemical industry, transport and agriculture produce huge amounts of dangerous waste gases and liquids, leading to soil, air and water contamination. One more modern threat - international terrorism - demands that scientists make efforts to apply new principles and technologies to protect society against chemical, biological, radiological and nuclear (CBRN) attacks and to develop novel effective technologies for the remediation of large contaminated areas. Accordingly, the main goal of this book is to bring together experts (theorists, experimentalists, engineers and technologists) for an extensive discussion covering: novel principles for functional nanostructures and detector fabrication and implementation, the development of novel technologies for the deactivation of CBRN agents, their experimental realization and their application in novel monitoring and control systems, and technological processes for soil and water remediation, with a view to environmental protection and defence against CBRN-based terrorism. In keeping with the book’s main goal, the following topics are highlighted and discussed: - Sensors and detectors - detection of chemicals, principles of “artificial nose” and chemical “micro-lab on a chip” design, surface and underground water quality monitoring systems, molecular electronics, superconducting electronic devices, quantum detectors and Qubits. - Environmental protection and CBRN - detection of infrared, microwave, X-ray and terahertz radiation. Principles for novel IR-, UV-, and Terahertz-wave devices for the detection of low-contrast objects. - Novel technological processes for CBRN destruction and deactivation. All these topics are strongly interrelated, both with regard to fundamental aspects and to fabrication and implementation technologies; in addition, they are highly promising for application in novel functional devices, computer logics, sensing and detection of low-concentration chemicals, weak and extremely weak magnetic and microwave fields, infrared and ultraviolet radiation. Given its scope, the book will be a useful and interesting guide for a broad readership of engineers, scientists, PhD students and experts in the area of defence against environmental terrorism.