Fe-57 Mossbauer study of the interstitial nitrogen atom effects of NdFe10.5V1.5Nx

Magnetic and Fe-57 Mossbauer spectra measurements were carried out to study the interstitial nitrogen atom effects in the NdFe10.5V1.5Nx (0 less than or equal to x less than or equal to 2.1) compounds. It is found that satura tion magnetization, magnetocrystalline anisotropy, hyperfine fields, and is omer shifts of NdFe10.5V1.5Nx are strongly enhanced upon nitrogenation, due to magneto-volume effects and chemical bonding effects of nitrogen atoms. On the basis of the variation of isomer shifts and hyperfine fields as a fu nction of nitrogen concentration, and by using a set of phenomenological fo rmulas, the contributions of magneto-volume effect and the chemical bonding effect to the hyperfine parameters are successfully separated. The pure ma gneto-volume effect and the chemical bonding effect of the nitrogen atoms w ill give a positive contribution to the average hyperfine fields and isomer shifts of the Fe atoms in the NdFe10.5V1.5Nx nitrides. (C) 1998 American I nstitute of Physics.