Introduction

This book is concerned with a speci c aspect of the structure of natural and technological materials-the crystallographic orientation of its component units. The crystallographic orientation, or in this context simply orientation, refers to how the atomic planes in a volume of crystal are positioned relative to a xed reference. This characteristic applies to all solids whose structure is crystalline, including minerals, ceramics, semiconductors, superconductors, and metals. Almost all of these materials are polycrystalline (rather than mono-or bicrystalline), and their component units are referred to as crystals or “grains.”