High-temperature magnetoresistance study of a magnetic tunnel junction

Abstract The thermal stability and the spin transportation phenomenon at room temperature and 140 ° C of a series of magnetic tunneling junctions with the structure of bottom electrode/PtMn/Pinned layer/ AlO x /CoFe/NiFe/top electrode have been investigated. The MR ratio decreases from 33.5% at room temperature to 29% at 140 ° C. The MR ratio at room temperature increases roughly 0.8% after thermal treatment at temperatures above 60 ° C. This is related to the thermal relaxation of the strains existing in the samples.