This book provides a collection of contributed chapters, delivering a comprehensive overview of topics related to the synthesis and crystal growth of nitride compounds under supercritical ammonia conditions. Focusing on key chemical and technological aspects of ammonothermal synthesis and growth of functional nitride compounds, the book also describes many innovative techniques for in-situ observation and presents new data fundamental for materials synthesis under ammonothermal conditions. With its detailed coverage of many thermodynamic and kinetics aspects, which are necessary for understanding and controlling crystal growth, this contributed volume is the ideal companion to materials chemists and engineers at any point in their journey in this rich and exciting field.