Determinazione di precisione dei parametri reticolari da fotogrammi di monocristallo

摘要

The intention of this report is to give:na) a review of the methods for routine precision determinationnof lattice parameters of single crystals using the conventional Weissen . berg camera and the Buerger precession camera;nb) the outline of a method for correcting Bragg angles devised by the authors as a result of the error analysis of the lattice parameters measured from Weissenberg photographs with or without Christ's or Pabst's calibrations. In this method use is made of a "local" d-values interpolation from a suitable standard powder diffraction pattern (ZnO syntered at 1200° C). Routine measurements of unit cell parameters can thus be carried out, accurately enough for X-ray crystal and molecular structure determinations.