Bulk and interface spin-orbit torques in Pt/Co/MgO thin film structures
Fuente:
arXiv
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866910362047086592 |
|---|---|
| author | Gabor, M. S. Belmeguenai, M. Miron, I. M. |
| author_facet | Gabor, M. S. Belmeguenai, M. Miron, I. M. |
| contents | We investigate the origin of spin-orbit torques (SOTs) in archetypical Pt/Co/MgO thin films structures by performing harmonic Hall measurements. The behaviour of the damping like (DL) effective field ($h_{DL}$) with varying the Pt layer thickness and the Co layer thickness indicates that bulk spin-Hall effect (SHE) in Pt is mainly responsible for DL-SOT. The insertion of a Pd ultrathin layer at the Pt/Co interface leads to a step decrease in $h_{DL}$, attributed to the modification of interfacial spin transparency. Further increase in Pd thickness led to a reduction of the interfacial spin-orbit coupling (iSOC) quantified by the decrease in the surface magnetic anisotropy. The consistent insensitivity of $h_{DL}$ to variations in iSOC at the bottom Pt/Co interface and oxidation at the top Co/MgO interface provides additional evidence for the bulk SHE origin of DL-SOT. The strong reduction in the field-like (FL) torque effective field ($h_{FL}$) with decreasing iSOC at the Pt/Co interface points to the interfacial nature of FL-SOT, either due to iSOC induced interfacial spin-currents or to the Rashba-Edelstein effect at the Pt/Co interface. Furthermore, we demonstrate that a FL-SOT develops at the top Co/MgO interface opposing the one generated at the bottom Pt/Co interface, whose strength increases with Co/MgO interfacial oxidation, and attributed to the Rashba-Edelstein effect. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2403_06627 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Bulk and interface spin-orbit torques in Pt/Co/MgO thin film structures Gabor, M. S. Belmeguenai, M. Miron, I. M. Materials Science We investigate the origin of spin-orbit torques (SOTs) in archetypical Pt/Co/MgO thin films structures by performing harmonic Hall measurements. The behaviour of the damping like (DL) effective field ($h_{DL}$) with varying the Pt layer thickness and the Co layer thickness indicates that bulk spin-Hall effect (SHE) in Pt is mainly responsible for DL-SOT. The insertion of a Pd ultrathin layer at the Pt/Co interface leads to a step decrease in $h_{DL}$, attributed to the modification of interfacial spin transparency. Further increase in Pd thickness led to a reduction of the interfacial spin-orbit coupling (iSOC) quantified by the decrease in the surface magnetic anisotropy. The consistent insensitivity of $h_{DL}$ to variations in iSOC at the bottom Pt/Co interface and oxidation at the top Co/MgO interface provides additional evidence for the bulk SHE origin of DL-SOT. The strong reduction in the field-like (FL) torque effective field ($h_{FL}$) with decreasing iSOC at the Pt/Co interface points to the interfacial nature of FL-SOT, either due to iSOC induced interfacial spin-currents or to the Rashba-Edelstein effect at the Pt/Co interface. Furthermore, we demonstrate that a FL-SOT develops at the top Co/MgO interface opposing the one generated at the bottom Pt/Co interface, whose strength increases with Co/MgO interfacial oxidation, and attributed to the Rashba-Edelstein effect. |
| title | Bulk and interface spin-orbit torques in Pt/Co/MgO thin film structures |
| topic | Materials Science |
| url | https://arxiv.org/abs/2403.06627 |