Oxide layer boron leads to reduced symmetry spin filtering magnetic tunnel junctions
| dc.creator | Stewart, Derek A. | |
| dc.date | 2009-04-28 | |
| dc.date.accessioned | 2026-07-07T13:09:51Z | |
| dc.date.available | 2026-07-07T13:09:51Z | |
| dc.description | Experimental studies of FeCoB/MgO/FeCoB tunnel junctions indicate that boron diffuses into MgO during rf-sputtering and forms polycrystalline Mg-B-O regions. These tunnel junctions provide high tunneling magnetoresistance values and low RA products. However the crystal structure of the Mg-B-O region remains unknown. Using density functional techniques, I examine three potential Mg(B) oxides including Mg$_{2}$B$_{2}$O$_{5}$ (monoclinic and triclinic) and the orthorhombic mineral Kotoite (Mg$_3$B$_2$O$_6$). Kotoite is the best candidate for formation in magnetic tunnel junctions. The (100) surface of Kotoite has a good lattice match with (001) MgO and could template neighboring FeCo into bcc layers during annealing. Complex band structure analysis of Kotoite shows that the C$_{2v}$ $\tildeΔ_1$ band has a much smaller imaginary k component than the C$_{2v}$ $\tildeΔ_4$ band. Based on symmetry analysis, the majority spin $Δ_1$ band in FeCo should couple well with the Kotoite $\tildeΔ_1$ band, while the minority FeCo $Δ_5$ will couple partially with the $\tildeΔ_4$ band. Kotoite provides a new route to high tunneling magnetoresistance based on spin filtering by a lower symmetry oxide region. | |
| dc.description | 11 pages, 4 figures, submitted | |
| dc.identifier | https://arxiv.org/abs/0904.4475 | |
| dc.identifier | http://arxiv.org/abs/0904.4475 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/228876 | |
| dc.subject | Materials Science | |
| dc.subject | Mesoscale and Nanoscale Physics | |
| dc.title | Oxide layer boron leads to reduced symmetry spin filtering magnetic tunnel junctions | |
| dc.type | text |