Low critical current density for spin-transfer torque in Fe–MgO granular film at room temperature.

From a practical point of view, a critical issue for the spin transfer effect is the reduction of the critical switching current density J_c. Over the past few years, the reported J_c at room temperature is in the range of 10⁶ A cm⁻². Here we report a low critical switching current density J_c of about 4.2 × 10³ A cm⁻² for spin transfer in Fe–MgO nanoscale granular film at room temperature, which is due to the low effective anisotropy field of the small Fe particles. [ABSTRACT FROM AUTHOR]