Mixtures of (N2)1−x : (O2)x at High Pressures and Low Temperatures

We performed Raman measurements at 18 K and pressures up to 25 GPa in order to construct a tentative phase diagram of the (N2)1−x:(O2)x–system at low temperatures. We varied the composition of the mixed system over the whole concentration range. Here we focused on the systems with high nitrogen concentration and pressures above 2 GPa. It is known that at room temperature oxygen is highly solvable in the δ–phase of N2. The experimental results show that oxygen suppresses the disorder–order transition δ → ∈−N2.