The detection of small differences in lattice constant at low temperature by an energy-dispersive X-ray diffractometer

A cryostat has been designed for an energy-dispersive X-ray diffractometer so that the specimen can be measured between 1.48 K and room temperature. Three powder samples can successively be measured at a fixed temperature by rotating the cryostat in steps of 120°. This design is very suitable particularly for detecting a slight change or difference, if any, in lattice constant among samples. A typical example is described of detecting the difference in lattice constant between ⁹²Mo and ¹⁰⁰Mo.