Synthesis of FeN₄ at 180?GPa and its crystal structure from a submicron-sized grain.

ABSTRACT: Iron tetra-nitride, FeN₄, was synthesized from the elements in a laser-heated diamond anvil cell at 180?(5)?GPa and 2700?(200)?K. Its crystal structure was determined based on single-crystal X-ray diffraction data collected from a submicron-sized grain at the synchrotron beamline ID11 of ESRF. The compound crystallizes in the triclinic space group P . In the asymmetric unit, the Fe atom occupies an inversion centre (Wyckoff position 1d), while two N atoms occupy general positions (2i). The structure is made up from edge-sharing [FeN₆] octa-hedra forming chains along [100] and being inter-connected through N-N bridges. N atoms form catena-poly[tetraz-1-ene-1,4-di-yl] anions [-N=N-N-N-]_? ^2- running along [001]. In comparison with the previously reported structure of FeN₄ at 135?GPa [Bykov et al. (2018). Nat. Commun. 9, 2756], the crystal structure of FeN₄ at 180?GPa is similar but the structural model is significantly improved in terms of the precision of the bond lengths and angles.

SUBMITTER: Bykov M 

PROVIDER: S-EPMC6176440 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature