Spin-orbit torques acting upon a perpendicularly magnetized Py layer
Abstract
We show that Py, a commonly used soft ferromagnetic material with weak anisotropy, can become perpendicularly magnetized while depositing on a Ta buffer layer with Hf or Zr insertion layers (ILs) and an MgO capping layer. By using two different approaches, namely, harmonic voltage measurement and hysteresis loop shift measurement, the dampinglike spin-orbit torque (DL-SOT) efficiencies from Ta/IL/Py/IL/MgO magnetic heterostructures with perpendicular magnetic anisotropy are characterized. We find that though Ta has a significant spin Hall effect, the DL-SOT efficiencies are small in systems with the Ta/Py interface compared to that obtained from the control sample with the traditional Ta/CoFeB interface. Our results indicate that the spin transparency for the Ta/Py interface is much less than that for the Ta/CoFeB interface, which might be related to the variation of spin mixing conductance for different interfaces.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 01, 2018
- Source ID
- 10.1063/1.5067251
Entities
People
- Chi-Feng Pai
- R. A. Buhrman
- Tian-yue Chen
- Tsung-yu Tsai
- Yongxi Ou
Organizations
- Cornell University
- Division of Materials Research
- National Science and Technology Council
- National Taiwan University
- Office of Naval Research