The optimum oxidation state of AlO/sub x/ magnetic tunnel junctions

In this paper we present results on how both the resistance and the magnetoresistance of magnetic spin-tunnel junctions depend on the oxidation time used to form the AlO/sub x/ barrier. The bias voltage dependence of junctions with barriers created with different oxidation times is measured and found to be optimal when the oxidation time is chosen to give sufficient oxygen for the barrier to be stoichiometric Al/sub 2/O/sub 3/. The oxygen content of the barrier was determined by Rutherford backscattering spectrometry and elastic recoil detection.