Magnetic property enhancement of melt-spun Pr[sub 2]Fe[sub 23]B[sub 3] ribbons with dilute Ti substitution.

The phase evolution and magnetic properties of Pr[SUB2]Fe[SUB23]B[SUB3] and Pr[SUB2](Fe[SUB0.975]Ti[SUB0.025])[SUB23]B[SUB3] melt-spun ribbons have been investigated. For Pr[SUB2]Fe[SUB23]B[SUB3] spun at 25 m/s, the magnetically hard Pr[SUB2]Fe[SUB14]B phase coexists with α-Fe, Pr[SUB2]Fe[SUB23]B[SUB3], and Fe[SUB3]B when annealed at temperatures above 700 °C, while merely two phases, namely, Pr[SUB2]Fe[SUB14]B and α-Fe, coexist if annealed above 800 °C. Because of the excessive annealing, these ribbons exhibit large grain sizes that lead to low B[SUBr] and [SUBi]H[SUBc] values. A slight substitution of Ti for Fe in (Pr[SUB2]Fe[SUB0.975]Ti[SUB0.025])[SUB23]B[SUB3] suppresses the formation of metastable Pr[SUB2]Fe[SUB23]B[SUB3] phase and leads to the presence of large amount of Pr[SUB2]Fe[SUB14] B and α-Fe phases of fine grain sizes in the matrix even at low annealing temperature (i.e., T[SUBH] = 650 °C). As a result, the magnetic properties improve remarkably from (B)r = 6.7 kG, [SUBi]H[SUBc] = 1.5 kOe and (BH)[SUBmax] = 1.7 MG Oe of the ternary Pr[SUB2]Fe[SUB23]B[SUB3] to B[SUBr] = 9.9 kG, [SUBi]H[SUBc] = 5.7 kOe and (BH)[SUBmax] = 15.0 MGOe of the Pr[SUB2]Fe[SUB0.975]Ti[SUB0.025])[SUB23]B[SUB3]. [ABSTRACT FROM AUTHOR]