Magnetic and magnetostrictive properties in amorphous (Tb0.27Dy0.73)(Fe1−xCox)2 films

Magnetic and magnetostrictive properties have been investigated for amorphous (Tb0.27Dy0.73)(Fe1−xCox)2 thin films. An increase in the 3d magnetic moment due to the enhancement of T–T interactions in substituted (Fe, Co) alloys was found. This leads to stronger R–(Fe, Co) exchange energies and then to enhancements of R–sublattice magnetization as well as magnetostriction in these amorphous R(Fe, Co) thin films. In addition, a well-defined in-plane anisotropy is created by magnetic-field annealing for the Co-rich films. A large magnetostriction of 480×10−6 developed in low fields of 0.3 T was observed for films with x=0.47 after magnetic-field annealing. The differing roles of Fe and Co atoms on the magnetization process have also been discussed.