An X-ray diffractometer for studying the effect of external fields on the structure and electron distribution of single crystals

A new four-circle X-ray diffractometer (RMD) for single crystals is described that has only one (horizontal) axis of specimen rotation and a movable X-ray tube and detector. The diffractometer is characterized by the equatorial geometry. The equatorial plane rotates about the χ axis lying in this plane whereas the φ axis is fixed. This permits the use of various external (electromagnetic, magnetic etc.) fields applied to specimens along the φ axis. The angles between this direction and all the other crystallographic directions in the specimen remain constant in the course of intensity measurements. The designed RMD diffractometer allows the study of structural changes and electron distribution variations in a crystal subjected to external actions. The geometry and the design of the goniometer are considered in detail. Experiments carried out on the RMD diffractometer have demonstrated its efficiency for precision X-ray structure analysis.