Phase-Field Simulation of Strain-Assisted Current-Induced Magnetization Dynamics in a Magnetic Tunnel Junction

We investigated the effect of substrate misfit strain theoretically by using a phase-field microelasticity model in a simple sandwich structure of a magnetic tunnel junction with perpendicular anisotropy. The critical current for magnetization flipping decreases with increasing tensile strain except in the region above a threshold strain, which results from magneto-elastic coupling interaction between perpendicular magnetic anisotropy and substrate strain. Magnetization reversal speeds with different substrate strains and switching currents are also presented, which suggest ways to improve the magnetization switching efficiency and decrease the power consumption of magnetic devices.