This book has been compiled to give specialists, in areas that could be helped by tunneling spectroscopy, a rounded and relatively painless intro duction to the field. Why relatively painless? Because this book is filled with figures-A quick glance through these figures can give one a good idea of the types of systems that can be studied and the quality of results that can be obtained. To date, it has been somewhat difficult to learn about tunneling spectroscopy, as papers in this field have appeared in a diversity of scientific journals: for example. The Journal of Adhesion, J(}urnal (}f Catalysis, Surface and Interface Analysis, Science, Journal of the American Chemical Society, Physical Review-over 45 different ones in all, plus numerous conference proceedings. This diversity is, however, undoubtedly healthy. It indicates that the findings of tunneling spectroscopy are of interest and potential benefit to a wide audience. This book can help people who have seen a few papers or heard a talk on tunneling spectroscopy and want to learn more about what it can do for their field. Tunneling spectroscopy is presently in a transitional state. Its experi mental methods and theoretical basis have been reasonably well developed. Its continued vitality will depend on the success of its applications. Crucial to that success, as pointed out by Ward Plummer, is the adoption of tunneling spectroscopy by specialists in the areas of application.

Electron tunnelling spectroscopy as a research tool has strongly advanced understanding of superconductivity. This book explains the physics and instrumentation behind the advances illustrated in beautiful images of atoms, rings of atoms and exotic states in high temperature superconductors, and summarizes the state of knowledge that has resulted.

Inelastic Electron Tunneling Spectroscop~ or lETS, provides a unique technique for electronically monitoring the vibrational modes of molecul (;5 adsorbed on a metal oxide surface. Since the discovery of the phenomena by JAKLEVIC and LM1BE in 1966, lETS has been developed by a number of scientists as a method for studying the surface chemistry of molecular species adsorbed on aluminum oxide. Recent applications of lETS include investigations of physical and chemical adsorption of hydrocarbons, studies of catalysis by metal particles, detection and identification of trace substances in air and water, and studies of biological molecules and electron damage to such molecules. lETS has been employed to investigate adhesive materials, and studies are currently in prog ress to investigate corrosion species and corrosion inhibitors on aluminum and its alloys. Electronic transitions of molecules have also been studied by lETS. The recent development of the "external doping" technique, whereby molecu lar species can be introduced into fabricated tunnel junctions, opens the door for a vast new array of surface chemical studies by lETS. lETS is rap idly becoming an important tool for the study of surface and interface phe nomena. In addition to its role in surface studies, inelastic tunneling has proved extremely valuable for the study of the electronic properties of thin metallic films, and the recent discovery of light emission from inelastic tunneling promises to be of some importance in the area of device physics.

Within this work, the pairing mechanism of conventional (Pb) and unconventional superconductors (SrFe2(As1-xPx )2 , FeSe, FeSe/STO) was investigated experimentally by means of elastic and inelastic tunneling spectroscopy at temperatures down to 30 mK. The distinction between elastic and inelastic contributions to tunneling data was elaborated. The results help to identify conventional (phonon-mediated) and unconventional (e.g. spin-?uctuation mediated) superconductivity.

This work describes the experimental study of electron-boson interactions in superconductors by means of inelastic electron tunneling spectroscopy performed with a scanning tunneling microscope (STM) at temperatures below 1 K. This new approach allows the direct measurement of the Eliashberg function of conventional superconductors as demonstrated on lead (Pb) and niobium (Nb). Preparative experiments on unconventional iron-pnictides are presented in the end.

Scanning tunneling microscopy (STM) and its extensions have become revolutionary tools in the fields of physics, materials science, chemistry, and biology. These new microscopies have evolved from their beginnings asresearch aids to their current use as commercial tools in the laboratory and on the factory floor. New wonders continue to unfold as STM delivers atomic scale imaging and electrical characterization of the newly emerging nanometer world. This volume in the METHODS OF EXPERIMENTAL PHYSICS Series describes the basics of scanning tunneling microscopy, provides a fundamental theoretical understanding of the technique and a thorough description of the instrumentation, and examines numerous examples and applications. Written by the pioneers of the field, this volume is an essential handbook for researchers and users of STM, as well as a valuable resource for libraries.

This book presents a unified view of the rapidly growing field of scanning tunneling microscopy and its many derivatives. After examining novel scanning-probe techniques and the instrumentation and methods, the book provides detailed accounts of STM applications. It examines limitations of the present-day investigations and provides insight into further trends. "I strongly recommend that Professor Bai's book be a part of any library that serves surface scientists, biochemists, biophysicists, material scientists, and students of any science or engineering field...There is no doubt that this is one of the better (most thoughtful) texts." Journal of the American Chemical Society (Review of 1/e)