Effects of nitrogenation and composition on phase transformation and magnetic properties of Nd10Fe82B8-xMox (x=0 to 8) alloys

The effects of nitrogenation on the phase transformation and the magnetic p roperties of Nd10Fe82B8-xMox (x = 0 to 8) alloys prepared by mechanical all oying have been studied. For the alloys annealed at 850 degrees C for 20 mi n. Nd2Fe14B/alpha-Fe-type nanocomposite magnets are formed at x = 0 to 2. N d2Fe14B and Nd(Fe,Mo)(12) coexist in the alloys at x = 3 to 5, and the tetr agonal Nd(Fe,Mo)(12) with ThMn12 type structure is formed as main phase in the alloys at x = 6 to 8. With increasing Mo content I, the coercivity mu(0 )H(c) and the maximum magnetic energy product (BH)(max) of the annealed all oys first increase and reach maxima at x = 2. Upon nitrogenation, the Nd2Fe 14B compound is completely decomposed to form an N-containing amorphous mat rix and nanostructured alpha-Fe as well as an Nd(Fe,Mo)(12)N-delta compound . With increasing Mo content x, mu(0)H(c) and (BH)(max) of the nitrided all oys increase sharply at x = 6 due to the formation of a great amount of nea rly single-phase Nd(Fe,Mo)(12)N-delta.