X-ray diffraction studies of N2–Ar solid solutions
Abstract
X-ray studies of the phase diagram of nitrogen–argon solid solutions have been carried out. It was established that near the solidus line there is an almost infinite mutual solubility of the components in the N2–Ar system, which rapidly decreases as the temperature is lowered. It is shown that the solubility diagram obtained earlier by Barrett and his co-workers is not the equilibrium one. A region of coexistence of two phases of hexagonal symmetry was found at high temperatures, bounded by a binodal curve with the critical point at T≃56 °K. The conditions for obtaining supercooled hexagonal solutions containing 40−60% N2 are explained. From the results obtained it can be suggested that at low temperatures states with a “frozen-in” position of the molecular axes are formed in the orientational subsystem.