Role of CoFeB thickness in electric field controlled sub-100 nm sized magnetic tunnel junctions
| Autor: | Jian Cheng Huang, Sze Ter Lim, Ernult Franck Gerard, James Lourembam |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Magnetoresistance Condensed matter physics General Physics and Astronomy Pulse duration 02 engineering and technology Coercivity 021001 nanoscience & nanotechnology 01 natural sciences lcsh:QC1-999 Magnetization Magnetic anisotropy Electric field 0103 physical sciences Perpendicular 0210 nano-technology Anisotropy lcsh:Physics |
| Zdroj: | AIP Advances, Vol 8, Iss 5, Pp 055915-055915-6 (2018) |
| ISSN: | 2158-3226 |
| Popis: | We report a comprehensive study on the role of the free layer thickness (tF) in electric-field controlled nanoscale perpendicular magnetic tunnel junctions (MTJs), comprising of free layer structure Ta/Co40Fe40B20/MgO, by using dc magnetoresistance and ultra-short magnetization switching measurements. Focusing on MTJs that exhibits positive effective device anisotropy (Keff), we observe that both the voltage-controlled magnetic anisotropy (ξ) and voltage modulation of coercivity show strong dependence on tF. We found that ξ varies dramatically and unexpectedly from ∼−3 fJ/V-m to ∼−41 fJ/V-m with increasing tF. We discuss the possibilities of electric-field tuning of the effective surface anisotropy term, KS as well as an additional interfacial magnetoelastic anisotropy term, K3 that scales with 1/tF2. Voltage pulse induced 180° magnetization reversal is also demonstrated in our MTJs. Unipolar switching and oscillatory function of switching probability vs. pulse duration can be observed at higher tF, and agrees well with the two key device parameters — Keff and ξ. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|