Differential scanning calorimetric study of the solid—solid transitions in NaNO2-base binary alloys with NaNO3 and KNO2

Up to ～1 mol % maximum solid solubility of KNO₂ or NaNO₃, the two solid—solid transition temperatures in NaNO₂-base alloys decrease ～11±4 deg per mol % solute, except that the upper transition temperature is hardly altered by alloying with KNO₂. From the data on alloys with KNO₂, the ratio of the entropy of the upper transition to the lower transition in NaNO₂ is estimated as 0.35±0.07.