Spin transfer switching and spin polarization in magnetic tunnel junctions with MgO and AlOx barriers

Publisher Website
Google Scholar
Abstract
We present spin transfer switching results for MgO based magnetic tunnelingjunctions(MTJs) with large tunneling magnetoresistance (TMR) ratio of up to 150% and low intrinsic switching current density of 2 – 3 × 10 6 A ∕ cm 2 . The switching data are compared to those obtained on similar MTJ nanostructures with AlO x barrier. It is observed that the switching current density for MgO based MTJs is 3 to 4 times smaller than that for AlO x based MTJs, and that can be attributed to higher tunneling spin polarization (TSP) in MgO based MTJs. In addition, we report a qualitative study of TSP for a set of samples, ranging from 0.22 for AlO x to 0.46 for MgO based MTJs, and that shows the TSP (at finite bias) responsible for the current-driven magnetization switching is suppressed as compared to zero-bias tunneling spin polarization determined from TMR.
All Related Versions