AN AUTOMATIC 4-CIRCLE DIFFRACTOMETER DESIGNED FOR PRECISE LATTICE-PARAMETER DETERMINATION

The method introduced by Bond (1960) appears to be the most convenient for high-precision lattice-parameter determination in a broad temperature range for a large number of single-crystalline materials. The Bond diffractometers built up to now require very accurate and time-consuming setting of specimens. The setting must be checked and corrected after each temperature change, which makes the experiment rather tedious. The authors have reconstructed the KUMA KM4 automatic four-circle diffractometer to fit the requirements of the Bond method. The collimator with exchangeable slits is much longer (240mm), which improves the collimation and allows measurement of the intensities of X-ray reflections with 20<168 at both sides of the primary beam. The measurements are automatic and can be performed with or without a graphite monochromator.