Magnetic properties, magnetoresistance (MR), and spin-transfer switching of magnetic tunnel junctions having a structure of Co60 Fe20 B20 3 nm/MgO 1 nm/ (Co75 Fe25) 80-X Cr (V) X B20 2 nm (X=0-25) were investigated. Magnetization of the (Co-Fe)-(Cr, V)-B free layer decreased from 1.2 T before substitution to 0.6 T at Cr of 10% (0.8 T at V of 10%). The MR ratio and a resistance-area product (RA) before substitution were, respectively, about 130% and about 2 μ m2. The MR ratio decreased to 80% at Cr of 10% and 40% at V of 10%. The RA values were almost independent of the composition. The intrinsic switching current density (Jc0) decreased from 15 to 8 MA/ cm2 at Cr of 10% and 12 MA/ cm2 for V of 10%. Upon the further increase in Cr and V, stable switching was difficult to observe. In summary, Jc0 decreased to half in the case of Cr, but the effect was small for V.
ASJC Scopus subject areas
- Physics and Astronomy(all)