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▲ [16a-D704-1] Post-annealing effect on voltage induced coercivity change in Pt/Ru/Co/CoO/TiOx system
Keywords:spintronics, voltage control
We have reported a large voltage induced Hc changes after optimal post-annealing in Pt/Ru/Co/CoO/amorphous TiOx.[1] In this study, we investigated the effect of post-annealing on Pt/Ru/Co/CoO/amorphous TiOx structures more detail. From magnetization curve under bias-voltage, we found that annealing at 350 ºC results in an increase in squareness and Hc, indicating an enhancement of PMA. Accompanying this improvement in PMA, a large voltage induced Hc change was observed in the 350 ºC annealed sample. STEM-EDX analysis confirmed that Co atoms diffused into Pt, and capacitance and XAS measurements suggest that a part of CoO is reduced, by the post-annealing. XMCD measurements revealed that annealing causes an increase in the interfacial orbital magnetic moment. Our results indicate that the PMA and VCMA at the Co/oxide upper interface are increased possibly due to the interdiffusion of Co and Pt, by post-annealing. [1] T. Nozaki et al., Sci. Rep. 11, 21448 (2021).