Magnetization Dynamics in Two Novel Current-Driven Spintronic Memory Cell Structures
Type
ThesisAuthors
Velazquez-Rizo, Martin
Advisors
Fariborzi, Hossein
Committee members
Ohkawa, Kazuhiro
Manchon, Aurelien

Date
2017-07Embargo End Date
2018-08-01Permanent link to this record
http://hdl.handle.net/10754/625242
Metadata
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At the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis became available to the public after the expiration of the embargo on 2018-08-01.Abstract
In this work, two new spintronic memory cell structures are proposed. The first cell uses the diffusion of polarized spins into ferromagnets with perpendicular anisotropy to tilt their magnetization followed by their dipolar coupling to a fixed magnet (Bhowmik et al., 2014). The possibility of setting the magnetization to both stable magnetization states in a controlled manner using a similar concept remains unknown, but the proposed structure poses to be a solution to this difficulty. The second cell proposed takes advantage of the multiple stable magnetic states that exist in ferromagnets with configurational anisotropy and also uses spin torques to manipulate its magnetization. It utilizes a square-shaped ferromagnet whose stable magnetization has preferred directions along the diagonals of the square, giving four stable magnetic states allowing to use the structure as a multi-bit memory cell. Both devices use spin currents generated in heavy metals by the Spin Hall effect present in these materials. Among the advantages of the structures proposed are their inherent non-volatility and the fact that there is no need for applying external magnetic fields during their operation, which drastically improves the energy efficiency of the devices. Computational simulations using the Object Oriented Micromagnetic Framework (OOMMF) software package were performed to study the dynamics of the magnetization process in both structures and predict their behavior. Besides, we fabricated a 4-terminal memory cell with configurational anisotropy similar to the device proposed, and found four stable resistive states on the structure, proving the feasibility of this technology for implementation of high-density, non-volatile memory cells.Citation
Velazquez-Rizo, M. (2017). Magnetization Dynamics in Two Novel Current-Driven Spintronic Memory Cell Structures. KAUST Research Repository. https://doi.org/10.25781/KAUST-818N8ae974a485f413a2113503eed53cd6c53
10.25781/KAUST-818N8