Crystal and Magnetic Structures of Perovskite-derived Nitrides

Perovskite oxides are common but nitride analogues are rare. We recently discovered a new high-pressure method to prepare nitride perovskites exemplified on bulk-phase LaReN3 Here, we propose to study the new LaNiO2-type (infinite layer) NdReN2 defect perovskite as well as the K2NiF4-type La2WN4 Ruddlesden-Popper nitride by powder neutron diffraction to determine their nuclear and magnetic structures. NdReN2 crystallizes in a 2x1x2 distortion variant of the LaNiO2-type structure (SG Cmmm, a = 7.9165(4), b = 6.80606(8), c = 3.9591(2) Å). The distortion is created by an ordered displacement of the heavy atoms Nd and Re from their special positions in the tetragonal LaNiO2-type model. It also has an antiferromagnetic ordering at TN = 16 K.