Structure and magnetic properties of melt-spinning Pr(Fe0.6Co0.4)2 alloys

Pr(Fe0.6Co0.4)(2) ribbons were prepared by melt spinning with different wheel speeds from 35 to 45 m/s. Their structure, magnetic properties, and thermal stability are investigated. At a wheel speed of 35 m/s, the ribbon consists of a mixture of Pr(Fe,Co)(2) cubic Laves phase and some noncubic phases. An almost Pr(Fe,Co)(2) nanocrystalline single phase with a Curie temperature of 305 degrees C is obtained at a wheel speed of 40 m/s. Except for Pr(FeCo)(2) phase a small amount of amorphous phase is observed with increasing wheel speeds to 45 m/s. Pr(Fe,Co)(2) phase becomes unstable and decomposes above 770 degrees C. The resin-bonded Pr(Fe,Co)(2) nanocrystalline phase which is obtained at a wheel speed of 40 m/s combines high magnetostriction (lambda(parallel to)-lambda(perpendicular to)=140 ppm), with significant coercivity, H-i(c)=5 kOe. (C) 2000 American Institute of Physics. [S0021-8979(00)18808-5].