Changes of nitrides characteristics in Li–N system synthesized at different pressures

•Lithium nitride samples were obtained in Li–N system at nitrogen pressure 1–10 atm.•Lithium nitride subjected to decomposition gets converted into carbonate.•β-Modification was achieved at a pressure 500 times lower than that required.•Structures with smaller crystallite size are created as the N pressure increases.•N content in the formed nitride structures increases with pressure.

For the Li–N system samples were obtained at pressures of nitrogen from 1 to 10 atm. Energy-dispersive X-ray (EDX) spectrum of a sample of Li–N subjected to degradation shows that lithium nitride turned into carbonate as evidenced by the predominant content of carbon and oxygen. Upon synthesis of lithium nitride at a positive pressure of nitrogen, the β-modification is formed, which can be achieved at a pressure 500 times lower than that described in literature, required to create a high-pressure phase. The increase in carbon content with increasing of synthesis pressure of lithium nitride confirms the change in stoichiometry of its structure formed with high nitrogen content.