Expert coverage of the physics and mathematics of diffusion-reactions in solids and melts This book presents a unified treatment of diffusion and reaction in a wide variety of oxides-with a special emphasis on the reactive molecules of water, hydrogen, and oxygen. The author proposes new ways of understanding diffusion and reaction in oxides and in silica glass, presents new mathematical treatments of diffusion-reaction, and offers a new discussion of the oxidation state. Helpful data tables cover the activation energies of water and oxygen diffusion in oxides; the diffusion of dopants in silicon; the ionic porosity of crystalline and amorphous oxides; and the diffusion of a large number of elements in silicon. The book features advanced discussions of: * Diffusion and reaction in solids and in relation to solid structure * Diffusion and reaction of water in silica glass, quartz, obsidian, and all oxides * Diffusion and reaction of hydrogen in oxides * Diffusion and reaction of oxygen in oxides * The oxidation state * Diffusion in silicon Diffusion of Reactive Molecules in Solids and Melts presents an up-to-date and comprehensive survey of the subject written for geologists, professionals working in fiber optics, graduate students, and researchers in materials science and solid-state physics.