Phase diagram of the binary system CsNO3-LiNO3 - Activities in the liquid

Phase diagram of the binary system CsNO3-LiNO3 has been drawn by using simu ltaneously direct and differential thermal analysis between 323 and 723 K. This system is characterized by a congruent intermediate equimolar compound with melting point at 463 K, two eutectic reactions at 447 and 433 K; the eutectic points are respectively at 0,47 and 0,63 mol fraction of LiNO3; a plateau due to the phase transition of CsNO3 at 428 K and an other one at 3 33 K due to the formation of CsLi(NO3)(2). The miscibility in solid state s eems to be nil or negligible. These results associated with some other ther modynamic data have been used to calculate the activities of the constituen ts along the liquidus curve and the activities of the liquid constituents a t 723 K. The binary liquid (Cs-Li)NO3 exhibits a negative deviation from th e ideal behaviour.