A VACUUM PATH X-RAY DIFFRACTOMETER FOR PRECISION RELATIVE LATTICE PARAMETER MEASUREMENTS ON SINGLE CRYSTALS

摘要

A vacuum path X-ray diffractometer designed for lattice parameter measurements on single crystals is described. It is an instrument of high precision approaching 1 part in 10 or better, and is also capable of moderately high accuracy of approximately 1 part in 10 . The instrument is conceptually a variation of an earlier design but various factors are introduced to facilitate convenient experimental conditions. Scanning is automatic and provision is made on the instrument for a large working volume to accommodate auxiliary environmental equipment for the specimen. The mounting and measurement procedure is described and a sample calculation of lattice parameter with associated accuracy and precision is given. A discussion of the errors encountered in high precision measurements of this type concludes the report.