Discovery of the Last Remaining Binary Platinum‐Group Pernitride RuN₂

Abstract

The last remaining marcasite-type RuN2 was successfully synthesized by direct chemical reaction between ruthenium and molecular nitrogen above the pressure of 32 GPa. For the first time, we found that Ru 4d is weakly hybridized with N 2p in the structure by using transmission electron microscopy equipped with electron-energy-loss spectroscopy. Our finding give important knowledge about the platinum-group pernitride with respect to the chemical bonding between platinum-group element and nitrogen.

Diverse ruthenium nitrides stabilized under pressure: a theoretical prediction

“…As shown in Table 2, the calculated bulk modulus within GGA level is 298 GPa for Pnnm -RuN 2 , consistent with the previous theory 305.9 GPa33. This value is lower than the measured value 330 GPa17 and the calculated value 343 GPa18, caused by the difference between LDA and GGA methods938. The bulk modulus of Pnnm -RuN 2 is higher than that of RhN 2 (235 GPa)16, although lower than that of PtN 2 (372 GPa)910, IrN 2 (428 GPa)12, and OsN 2 (358 GPa)1218.…”

“…The calculated equilibrium lattice parameters of Ru nitrides with different stoichiometries and their formation enthalpies at 0 GPa are listed in Table 1 in comparison with available data171833. Our results agree well with the experimental lattice parameters within a maximum error of 1.0%, and also with the theoretical values, indicating the reliability of our calculations.…”

“…Recently, Pnnm -RuN 2 was synthesized by direct chemical reaction between ruthenium and molecular nitrogen above the pressure of 32 GPa17. The ground-state structure of RuN 2 was confirmed by the formation enthalpy curves as a function of pressure (Fig.…”

“…Later on, iridium, osmium and palladium were also found to form pernitrides under pressure12131415. Recently, marcasite-type rhodium and ruthenium pernitrides have been successfully synthesized as well1617. Among these nitrides, IrN 2 was found to have bulk modulus of 428 GPa1218, higher than most of previously synthesized materials.…”

Electronic bonding analyses and mechanical strengths of incompressible tetragonal transition metal dinitrides TMN2 (TM = Ti, Zr, and Hf)

“…and was finally determined to crystallize in the pyrite structure with a stoichiometry of 1:278. Thereafter, there have been considerable researches to search for other transition metal dinitrides, and so far as we know, the OsN 2 89, IrN 2 7910, PdN 2 10, RhN 2 11, and recently RuN 2 12 have been experimentally obtained in a direct chemical reaction between platinum group elements and molecular fluid nitrogen at high pressures and temperatures. The follow-up studies of their structures and mechanical properties have stimulated significant in their potential applications.…”