Neutron and X-ray powder diffraction study on the compound NdFe10.75V1.25Ny

The structural changes that occur in the compound NdFe10.75V1.25 due to nit rogenation have been investigated by neutron and X-ray powder diffraction. Nitrogen occupies less than 60% of the interstitial 2b site, even if the no minal nitrogen content in the structure is 2.4 N atoms/formula unit. The ex tra nitrogen is not believed to occupy other interstitial positions. V occu pies preferentially the 8i site in the non-nitrided case. However. this occ upancy decreases with increasing nitrogen content. The diffraction data sho w a strongly anisotropic behaviour of the profile parameters with nitrogen absorption due to the formation of anisotropic strain rather than stacking faults. (C) 1998 Elsevier Science S.A. All rights reserved.