Neutron diffraction studies of and

The structural and magnetic properties of the compounds and their nitrides have been studied by means of neutron diffraction and crystal-field calculation. Neutron diffraction studies show that the compounds and their nitrides exhibit -type structure, The vanadium atoms occupy 8i sites, and the nitrogen atoms occupy the 2b sites. It is also found that the direction of the magnetic moments changes from that of the ab-plane to that of the c-axis upon nitrogenation, which is consistent with the results of calculations based on crystal-field theory and the single-ion model.