Synthesis and Magnetic Properties of Nd(Fe,M)_12 (M=Mo,Ti) and their Compounds Nitrided by Chemical Reaction with Sodium Azide (NaN_3)

摘要

NdFe_11Ti, N(dFe_10.5Mo_1.5 and NdFe_10.75Mo_1.25 compounds have been successfully nitrogenated by heating a mixture of powdered alloys with sodium azide (NaN_3) at temperatures between 330 and 450deg.C. Structural and magnetic characterization yielded the following results: (l) The ThMn_12 structure of the original compounds is retained with the addition of nitrogen by chemical reaction with NaN_3. (2) The Curie temperature is enhanced by about 300deg.C. (3) The volume expansion was 4/100 (4) Particle size is found to be an important parameter for efficient nitrogenation at 330deg.C.