Ordering Process and Variant Selection under Magnetic Field in L1_0-type Co-50Pt and Fe-55Pd Alloys

摘要

Selected formation of variants under magnetic field in a diffusional process has been investigated by using Co-50Pt (at%) and Fe-55Pd (at%) alloys exhibiting A1 (disorder)-L1_0 (order) transformations. A single variant of the ordered phase is obtained in these alloys by applying a magnetic field during the early stage of ordering. The lowest magnetic field required for obtaining the single variant is about 0.5 T for the Co-50Pt alloy, and 4 T for the Fe-55Pd alloy in the present heat-treatment conditions. Such a difference could be due to the relation between nucleation barrier for the formation of the ordered phase and magnetocrystalline anisotropy at the nucleation stage.