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The phase formation of the (Nd _0.70 Pr _0.30−x Ce _x ) _2.28 Fe _13.58 B _1.14 (x = 0.10, 0.15, and 0.20; hereafter defined as Pr _20 Ce _10 , Pr _15 Ce _15 and Pr _10 Ce _20 , respectively) and (Nd _0.60 Pr _0.40−y Ce _y ) _2.28 Fe _13.58 B _1.14 (y = 0.10, 0.20, and 0.30; hereafter defined as Pr _30 Ce _10 , Pr _20 Ce _20 and Pr _10 Ce _30 , respectively) alloys that were prepared via the arc-melting method was investigated experimentally. The x-ray diffraction results revealed that all alloys annealed at 1173 K for 360 h consisted of a (NdPrCe) _2 Fe _14 B main phase with a tetragonal Nd _2 Fe _14 B-typed structure (space group P4 _2 /mnm) and an α -Fe minor phase, except for the Pr _10 Ce _30 alloy, which contained an additional CeFe _2 phase. The magnetic properties of the (Nd _0.70 Pr _0.30−x Ce _x ) _2.28 Fe _13.58 B _1.14 and (Nd _0.60 Pr _0.40−y Ce _y ) _2.28 Fe _13.58 B _1.14 ribbons that were prepared by melt spinning were examined. The remanence (B _r ) and maximum magnetic energy product ((BH) _max ) of the (Nd _0.70 Pr _0.30−x Ce _x ) _2.28 Fe _13.58 B _1.14 ribbons increased first and then decreased, whereas the coercivity (H _cj ) of the ribbons increased with an increase in Ce content. The B _r and (BH) _max of the (Nd _0.60 Pr _0.60−y Ce _y ) _2.28 Fe _13.58 B _1.14 ribbons increased, whereas the H _cj of the ribbons decreased gradually with an increase in Ce content. This changed behavior of magnetic properties is attributed to the variation of volume fraction of the α -Fe phase and different phase formations in the melt-spun ribbons. The Curie temperatures (T _c ) of all ribbons decreased slightly with Ce substitution, which results from the lower Curie temperatures of Pr _2 Fe _14 B and Ce _2 Fe _14 B. The Pr _10 Ce _30 ribbon with a higher Ce content exhibited optimal magnetic properties (B _r = 9.71 kGs, H _cj = 13.09 kOe, (BH) _max = 18.78 MGOe), which indicates that suitable magnetic properties of the Nd–Pr–Ce–Fe–B melt-spun ribbons can be achieved by alloy-composition and phase-formation design. |
