Solid Solution Formation Between Ammonium Nitrate and Potassium Nitrate

X-ray investigations by means of powder photographs show that solid solution formation between potassium nitrate and ammonium nitrate in simple admixture after grinding together may take place, and is considerably accelerated when the temperature is raised from ordinary temperatures to above 40 °C., at which NH4NO3 III is stable (transition temperature 32 °C.). The preparation of homogeneous mixed crystals of ammonium nitrate and potassium nitrate by co-crystallization of the salts from aqueous solution is described.