Composition related magnetic properties and coercivity mechanism for melt spun [(La0.5Ce0.5)1-xREx]10Fe84B6 (RE=Nd or Dy) nanocomposite alloys

Room temperature magnetic properties and coercivity mechanisms for nanocomposites [(La0.5Ce0.5)(1-x)REx](10)Fe84B6 (RE=Nd or Dy; x=0, 0.3, 0.5, and 0.7) alloys prepared by melt-spinning have been investigated. Nd and Dy substitutions can improve the hard magnetic properties, especially the coercivity of [(La0.5Ce0.5)(10)Fe84B6 alloy. The largest values of intrinsic coercivity H-c and maximum energy product (BH)(max) for the Dy substituted alloys are 714 kA/m and 41 KJ/m(3), respectively, whereas for Nd substituted alloys, H-c =365 kA/m and (BH)(max)=120 kJ/m(3) were obtained for x=0.7. The different elevated temperature behaviors were also found for Nd and Dy added alloys. The composition dependent coercivity mechanisms for Dy and Nd substituted alloys are evident based on the temperature dependence of coercivity described by domain wall pinning and reverse domain nucleation models. It is found that the domain wall pinning mechanism is possibly responsible for [(LaCe)Nd]FeB alloys while reverse domain nucleation is more likely responsible for[(LaCe)Dy]FeB alloys. (C) 2015 Elsevier B.V. All rights reserved