APPROACH TO THE STUDY OF THE DYNAMICS OF UNIT CELL PARAMETERS OF SINGLE CRYSTALS IN A WIDE TEMPERATURE RANGE ON THE EXAMPLE OF Ag0.39Li0.61GaSe2

We report a technique for the refinement of unit cell parameters by using external referencing for goniometer calibration, processing the 2D profile of diffraction reflection, and introducing corrections. The changes of unit cell parameters of the Ag0.39Li0.61GaSe2 single crystal is studied in the temperature range from 100 K to 480 K. As the volume of the tetragonal unit cell increases by 1%, parameter a increases by 0.6% and parameter c decreases by 0.3%.