Ideal stoichiometric technetium nitrides under pressure: A first-principles study

Technetium nitrides with various ideal stoichiometries have been investigated with the first-principle method at the pressures between 0–60 GPa. It have been found that there could be many stable technetium nitrides including Tc3N, Tc2N, TcN, Tc2N3, TcN2, TcN3, and TcN4, among which Tc3N and Tc2N subnitrides are synthesizable at zero pressure and could be applied to nuclear waste management, such as separate radioactive 99Tc from nuclear fuel cycle. Moreover, N-rich TcN3 and TcN4 exhibit remarkable bulk properties and can be potential ultrastiff and hard materials.