Synthesis and single-crystal X-ray diffraction characterization of novel yttrium nitrides under high pressures up to 175 GPa

The high-pressure chemistry and physical properties of rare earth metal nitrides are almost unknown. We demonstrated that even at moderate compression (~50 GPa) yttrium and nitrogen form a novel compound, Y5N14, with a new structural type and with three differently charged [N2]x- dimers. Theoretical studies predict the formation of exotic yttrium polynitrides near 100 GPa. Here, we propose a single-crystal X-ray diffraction (SCXRD) study of the Y-N system at pressures up to 175 GPa at ID27. The aims of the proposed experiments are a synthesis of new Y-N compounds at multimegabar pressure, characterization of their crystal chemistry and compressional behavior, tests of theoretical predictions, and search for regularities in polynitrogen chemistry.