Structural Investigation of Ti₄₀Zr₂₀Nb₂₀Ta₁₅₋ₓX₅ (X = Os, Ru)-N Complex Concentrated Nitrides and Pernitrides

High pressure modifies material composition by rearranging atomic structures, forming high-density phases. The synthesis of binary nitrides and pernitrides using diamond anvil cells (DAC) has gained interest due to the presence of polynitrogen anions in high-pressure experiments. Expanding nitride compositions to include up to five elements (5–35 at.%) enables the development of complex concentrated nitrides, unlocking new opportunities for functional materials. The planned synthesis of a Ti₄₀Zr₂₀Nb₂₀Ta₁₅₋ₓX₅ (X = Os, Ru; all in at.%) alloy under nitrogen pressures reaching 100 GPa at a temperature of 2500 K is expected to trigger novel chemical reactions, leading to the formation of new high-nitrogen-concentration phases. We expect to retain high-temperature phases formed directly during the reaction with nitrogen, facilitated by the presence of stabilisers. New high-density phases will be evaluated as potential candidates for high-energy-density materials.