Calorimetric Investigations of Phase Transitions in KNO₃Embedded Into Porous Glasses

Abstract

Results of the Differential Scanning Calorimetry (DSC) studies of porous glasses filled by KNO3 ferroelectric in wide temperature range are presented. Anomalous heat capacity of the potassium nitrate confined in nanoscale porous glasses with two different radius of pore 23 and 160nm show that the phase I-III transition temperature was slightly affected by particle size, whereas the phase III-II transition temperature significantly decreased. During the heating, the phase II-I transition temperature increased up to 12.5°C comparing to the bulk material. The lowering of the potassium nitrate particle size significantly reduced the phase I–liquid transition temperature.