This book contains the proceedings of a NATO Advanced Study Institute entitled "Characterization of Crystal Growth Defects by X-ray Methods' held in the University of Durham, England from 29th August to 10th September 1979. The current interest in electronic materials, in particular silicon, gallium aluminium arsenide, and quartz, and the recent availability of synchrotron radiation for X-ray diffraction studies made this Advanced Study Institute particularly timely. Two main themes ran through the course: 1. A survey of the various types of defect occurring in crystal growth, the mechanism...