EFFECTIVE MAGNETIC-ANISOTROPY OF NANOCRYSTALLINE ND-FE-TI-N HARD MAGNETIC-ALLOYS

The intermetallic compound Nd-Fe-Ti-N has been successfully synthesize d by a mechanical alloying process. The structure and magnetic propert ies of the sample have been studied using X-ray diffraction and magnet ic measurements. It is found that Nd9Fe83Ti8 alloy exhibits a nanocrys talline ThMn12-type tetragonal structure with lattice parameters of a = 0.8723 nm and c = 0.4896 nm. The saturation magnetization M-S and ef fective magnetic anisotropy K-eff of the compound have been determined by investigating magnetization processes. The calculated results base d on the law of approach to magnetic saturation have been successfully used to determine the constant K-eff The difference between observed and calculated values in magnetization is lower than 3%. Of all terms in the law of approach to saturation, it is the 1/H-2 term, which is a ttributed more to non-compensated anisotropy energy, that has the prev ailing effect for the compound. The absorption of nitrogen is found to increase unit cell volume, M-S and K-eff.