Spin Transfer Magnetization Switching Read/Write Cycle Test in MgO-Based Magnetic Tunnel Junctions

We present the results of spin transfer torque magnetization switching results for some MgO-based magnetic tunnel junctions (MTJ) with tunneling magnetoresistance (TMR) ratios of 38.6% to 200% and critical current densities of 1.032 times 10⁷ A/cm² down to 1.68 times 10⁶ A/cm². We observed 2.2 times 10⁴ stable read/write (R/W) cycles before failure under the spin transfer torque magnetization switching. The synchronized variations in both high and low magnetoresistance (MR) over the stable R/W cycles indicate that magnetization reversal into either high or low state occurs in parallel. We made a stability analysis for high and low MR distribution matching to a normalized fraction of stable cycles.