Magnetoresistance of Ir22Mn78-based top, bottom, and dual spin valves

Abstract The magnetoresistive properties of Co 75 Fe 25 /Ir 22 Mn 78 -based top (TSV), bottom (BSV), and dual type spin valves (DSV) by DC magnetron sputtering were investigated. The magnetoresistance (MR) ratio and exchange coupling field ( H ex ) of TSV were 5.6% and 430 Oe, respectively. For BSV the H ex values (1180 Oe) is much higher while MR ratio (3.6%) is reduced with respect to TSV. The blocking temperatures ( T B ) of the TSV and BSV were 250°C and 270°C, respectively. DSV, with MR ratio of 7.8% and H ex of 850/510 Oe, showed two different exchange loops.