Formation and magnetic properties of the RE-based compounds of type RE6Fe13-xAl1+x (RE = Pr, Sm, Gd)

Selected rare-earth (RE)-based delta-phase compounds of the composition RE6Fe13-xAl1+x(1 less than or equal to x less than or equal to 4) have been prepared and studied to ascertain their role in conveying coercivity to the so-called ferromagnetic bulk metallic glass (BMG) alloys (RE)(60)Fe30Al10. It was found that delta-phase does not exist for RE = Sm or Gd. However, nearly single delta-phase Pr-based compounds of the composition Pr6Fe13-xAl1+x in a range of Al concentration 1.5 less than or equal to x less than or equal to 3.5 were successfully synthesized. The antiferromagnetic behavior of the Pr-based delta-phase compounds is clearly seen from temperature-dependent magnetization measurements and the Neel temperature shows a quasi-linear decrease from 320 K to 115 K as x in Pr6Fe13-xAl1+x is increased from 1 to 4. The observed Al-concentration dependence of the Pr6Fe13-xAl1-x Neel temperatures is expected to be reflected in the magnetic behavior of the BMG alloys of composition Pr(60)e(30)Al(10). (C) 2004 Elsevier B.V. All rights reserved.