Calibration of CryojetHT and Cobra Plus Cryosystems used in X ray diffraction studies
CryoJetHT (Oxford Instruments) and Cobra Plus (Oxford Cryosystems) cryosystems, which are used for sample cooling in X ray diffraction experiments, have been calibrated. It is shown that the real temperature in the vicinity of the sample differs significantly (the deviation is as high as 8 10 K at low temperatures) from the temperature recorded by authorized sensors of these systems. The calibration results are confirmed by measurements of the unit cell parameters of GdFe3(BO3)4 single crystal in the temperature range of its phase transition. It is shown that, to determine the real temperature of a sample, one must perform an independent calibration of cryosystems rather than rely on their ratings.