Exchange biased spin polarizer with an embedded nano-oxide layer for a substantially lower switching current density

Abstract

The authors demonstrate that the spin polarizer in the form of an exchange biased ferromagnetic lead with an embedded nano-oxide layer can greatly enhance the spin transfer torque for the current induced magnetization switching. By applying it in spin valves, the switching current density (4x10(6) A/cm(2)) is one order lower and the resistance change (2.78 m Omega mu m(2)) is three times higher than those gotten by using a simple spin polarizer. This spin torque enhancement is attributed to the exchange bias pinning acting on the polarizer (the fixed layer) with effective support of the nano-oxide layer, which together lead to a much higher current spin polarization. (c) 2006 American Institute of Physics.