Elimination of systematic errors in applied accurate lattice parameter measurements

The method of accurate lattice parameters evaluation of polycrystalline materials is described which does not require direct quantitative data expressing the magnitude of systematic errors. Positions of a series of lines in back reflection region are used as input data for the computer evaluation, which are a linear function of the Bragg angle (or its complement) so that in the case of film measurement the diameter of the camera, and in the case of diffractometer measurement, the zero setting of the goniometer need not be determined independently. The method is illustrated in detail for back reflection film measurements in a cylinder camera. The method is aimed at making easy the applied accurate lattice parameter measurements.The author is deeply indebted to the late Professor M. E.Straumanis for valuable discussions in 1970 about the experimental problems of accurate lattice parameters measurements by film method and for making possible to use the original instruments in his laboratory. The author expresses his thanks to Mrs. V.Gregorová and Mr. M.Jelínek for taking part in the experiments.