Thermal stability of molybdenum diiodide

Methods of isothermal annealing, measurement of equilibrium pressure, X-ray phase and chemical analyses were used to study thermal stability of MoI2 in vacuum (1.33x10-3 Pa) and iodine atmosphere at 290-1470 K. It was established that solid molybdenum diiodide on heating up to 1000 K in static vacuum is impoverished with iodine in the limits of MoIsub(2-x) (x<=0.08) homogeneity region, and above 1000 K dissociates up to molybdenum. Molybdenum diiodide in static vacuum begins to evaporate above 870 K and in gaseous form is stable in Mo-I system up to 1080 K; then gaseous iodide begins to dissociate up to molybdenum. In iodine atmosphere solid MoI2 is stable up to 1270 K and gaseous - up to 1370 K