Study of the KNO$_{3}$–Al$_{2}$O$_{3}$ system by differential scanning calorimetry

The structural and the thermodynamic properties of potassium nitrate KNO$_{3}$ and its composites with nanosized aluminum oxide Al$_{2}$O$_{3}$ have been studied by differential scanning calorimetry. It has been found that an amorphous phase forms in composites $(1–x)$ KNO$_{3}$–$x$Al$_{2}$O$_{3}$. The thermal effect corresponding to this phase has been observed at 316$^\circ$C. It has been found that the phase transition heats of potassium nitrate decreased as the aluminum oxide fraction increased.