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.