Determination of the crystal structure of delta-MoN by neutron diffraction

摘要

We have determined the crystal structure of ordered hexagonal delta-MoN by use of powder X-ray diffraction and time-of-flight neutron diffraction. A disordered variety of the compound was first prepared by high-temperature ammonolysis Of MoCl5. This material has hexagonal symmetry with the space group P6(3)mc with a = 2.87(2) and c = 2.81 (1) Angstrom. Upon high pressure annealing, the N-atoms become ordered and the unit cell doubles in size: a = 5.73659(10) and c = 5.61884(17) Angstrom. The superconducting transition temperature increases from 4K in the disordered compound to 12.1 K in the ordered phase. (C) 2003 Elsevier Inc. All rights reserved.