High-pressure stability and ambient metastability of marcasite-type rhodium pernitride

作者：Niwa K^*; Terabe T; Suzuki K; Shirako Y; Hasegawa M

来源：Journal of Applied Physics, 2016, 119(6): 065901.

DOI：10.1063/1.4941436

High-pressure stability, ambient metastability, and high-pressure crystal chemistry of chemical bonds of marcasite-type RhN2 have been investigated using a laser-heated diamond-anvil cell up to a pressure of 70.6 GPa. High-pressure in-situ X-ray diffraction and Raman scattering measurements revealed that the marcasite-type RhN2 structure is stable up to 70.6 GPa and exhibited an order of axial compressibility of beta(c) > beta(b) > beta(a). This indicates that single bonded nitrogen dimer (N-N) plays an important role in the incompressibility of a-and b-axes than in that of the c-axis and stabilizes the marcasite-type structure at high-pressure. Field emission scanning electron microscopic analysis in combination with the energy dispersive X-ray spectroscopic measurements and the result of our previous study indicates that the marcasite-type RhN2 can be quenched to ambient pressure when the grain size is less than 100 nm. Our study together with other previous studies indicates that the ambient metastability of 4d platinum group pernitrides (RuN2, RhN2, and PdN2) decreases from ruthenium to palladium.

• 出版日期2016-2-14