講演情報
[9a-N303-5]First-principles study of hcp-Co1-xNix|h-BN|hcp-Co1-xNix magnetic tunnel junction
〇(PC)Ivan Kurniawan1, Keisuke Masuda1, Yoshio Miura1,2 (1.NIMS, 2.Kyoto Inst. Tech.)
キーワード：
tunneling magnetoresistance、2D material、first-principles
Lattice mismatch between MgO barriers and typical ferromagnetic electrodes often induces interfacial defects, limiting the magnetoresistance (MR) ratio in conventional magnetic tunnel junctions (MTJs). To address this, we investigate h-BN-based MTJs with hcp-Co1-xNix electrodes using first-principles calculations. h-BN offers better lattice matching and, as a chemically inert and structurally rigid 2D material, helps suppress interfacial disorder. We find that Ni doping enhances the MR ratio by shifting the minority-spin conductance peak toward the Brillouin zone center and expanding the zero-conductance region in the antiparallel configuration. It was also found that the conductance peak position and intensity depends on the interfacial distance, providing important insight into the origin of the large MR ratio in this system. These results deepen our understanding of spin-dependent tunneling in 2D-material-based MTJs and suggest a route for MR optimization through electrode design.