Introduction

Every active field of scientific investigation has a central, fundamental question that motivates continued research. One way to phrase the motivating question in materials research is: how can elements be combined to produce a solid with specified properties? This is, of course, a complicated question, and it is appropriate to break it up into at least three separate issues. First, when any given elements are combined under some controlled conditions, will they be immiscible, will they dissolve in one another, or will they react to form a compound and, if so, in what atomic ratio? Second, what structure will the product of this combination have and how is it influenced by the processing conditions? While this book deals almost exclusively with the atomic structure of the crystals, it is equally important to be able to specify the defect structure, the microstructure, and the mesoscale structure. Third, given the product phase or phases and the structure (at each length scale), what are the properties of this material? Addressing these fundamental questions in a systematic way requires familiarity with established principles of thermodynamics, kinetics, chemistry, physics, and crystallography. The present book is intended to provide a set of necessary (but not sufficient) skills to conduct materials research. Specifically, the scope of the course encompasses the description of the structure of crystalline matter, the experimental interrogation of crystalline structure, the origin of the cohesive forces that stabilize crystalline structures, and how these cohesive forces vary with the elements in the solid.