ABSTRACT
The object of the study was to select the CdS compound, in which the polymorphic transformation takes place at pressures and temperatures that are available for research under the conditions of pure hydrostatic pressure. Despite the fact that the phase transformation in CdS was investigated several times (a detailed review of experimental studies of CdS is in the monograph by K. Roomans [9.1] and in [9.8]), the T-P diagram of this compound and relationships of the phase transition have not as yet been reliably established due to the lack of studies in a wide temperature range under the conditions of purely hydrostatic pressure. In this regard, we conducted a dilatometric study of the CdS I-CdS II transition in the temperature range from room temperature
to 500ºC under hydrostatic pressures up to 24 kbar. The study was conducted on single crystal samples of semiconductor
purity wurtzite modifications from which cylindrical samples 3 mm in diameter and 10 mm long were produced. The study was conducted in the apparatus of the piston-cylinder type with internal heating using gasoline B-70 as the pressure-transmitting medium. The transformation was recorded in an inductive dilatometer with simultaneous recording of dilatometer readings, a thermocouple and a manganin pressure gauge in three EPP-09 electronic potentiometers. Sample heating and temperature measurements were carried out in the same way as in the study of transformations in rubidium halides (section 3.1).
