a b s t r a c t Due to the numerous applications of the alkali nitrate–silver nitrate systems (chemical processes, metallurgical research, transfers of thermal energy produced from solar radiation, etc.), the thermochemical properties and the phase diagram are important sources of information for a better exploitation of these systems. So, the heat capacities as well as the enthalpies of fusion and solid state transitions of rubidium nitrate, lithium nitrate and of the intermediate compounds Ag0.5Rb0.5NO3 and Li0.5Rb0.5NO3, in solid and liquid states, have been measured by differential scanning calorimetry (DSC). The enthalpies of formation of Ag0.5Rb0.5NO3 and Li0.5Rb0.5NO3 at 298 K have been deduced. © 2013 Elsevier B.V. All rights reserved.