Radiation Studies of Spin-Transfer Torque Materials and Devices

Spin-transfer torque film stacks and devices having in-plane magnetization were irradiated using a cobalt-60 gamma source. Samples were also exposed to 2 MeV and 220 MeV protons. Measurements of magnetization vs. field, ferromagnetic resonance, and tunnel magnetoresistance were performed on the film stacks before and after exposure to these sources and no changes were observed in the associated material properties. Spin-transfer torque devices were exposed to the same sources and show no changes in bit-state or write performance.