Improvement of high-angle double-crystal X-ray diffractometry (HADOX) for measuring temperature dependence of lattice constants. II. Practice

A HADOX diffractometer for measuring temperature dependence of lattice constants with a relative accuracy to one part in 10⁷ has been designed and constructed. Details of the structure and of the procedures for alignment and measurement are given together with the result of a performance test with silicon crystals. The observed value of the linear expansion coefficient of silicon is (2.72 ± 0.02) × 10^-6 K^-1 at 310 K; this is in good agreement with that previously given by a more accurate thermal expansion experiment and shows the applicability of this technique.