NdFe10.75Mo1.25 and NdFe11Ti alloys have been successfully nitrogenated by heating a mixture of powdered alloys with sodium azide (NaN3) at temperatures between 330 and 450 degreesC. Among the characterization techniques used to evaluate the final product, Mossbauer spectroscopy was invaluable for quantitative determination of 1-12 and alpha-Fe phases, after and before nitrogenation. The alpha-Fe phase increased indicated that a competition between the interstitially modified compound formation (alloy + N) and alloy dissociation occurred. This effect was more pronounced in Ti alloys nitrogenated at 450 degreesC.