Spin-orbit torque magnetometry by wide-field magneto-optical Kerr effect.

Sci Rep

Department of Materials Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan.

Published: April 2018

Magneto-optical Kerr effect (MOKE) is an efficient approach to probe surface magnetization in thin film samples. Here we present a wide-field MOKE technique that adopts a Köhler illumination scheme to characterize the current-induced damping-like spin-orbit torque (DL-SOT) in micron-sized and unpatterned magnetic heterostructures with perpendicular magnetic anisotropy. Through a current-induced hysteresis loop shift analysis, we quantify the DL-SOT efficiency of a Ta-based heterostructure with bar-shaped geometry, Hall-cross geometry, and unpatterned geometry to be |ξ | ≈ 0.08. The proposed wide-field MOKE approach therefore provides an instant and direct characterization of DL-SOT, without the need of any further interpretation on electrical signals.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5884866PMC
http://dx.doi.org/10.1038/s41598-018-23951-wDOI Listing

Publication Analysis

Top Keywords

spin-orbit torque
8
magneto-optical kerr
8
wide-field moke
8
torque magnetometry
4
magnetometry wide-field
4
wide-field magneto-optical
4
kerr magneto-optical
4
kerr moke
4
moke efficient
4
efficient approach
4

Similar Publications

Spin-Orbit Torque (SOT) Magnetic Random-Access Memory (MRAM) devices offer improved power efficiency, nonvolatility, and performance compared to static RAM, making them ideal, for instance, for cache memory applications. Efficient magnetization switching, long data retention, and high-density integration in SOT MRAM require ferromagnets (FM) with perpendicular magnetic anisotropy (PMA) combined with large torques enhanced by Orbital Hall Effect (OHE). We have engineered a PMA [Co/Ni] FM on selected OHE layers (Ru, Nb, Cr) and investigated the potential of theoretically predicted larger orbital Hall conductivity (OHC) to quantify the torque and switching current in OHE/[Co/Ni] stacks.

View Article and Find Full Text PDF

Enhancing Rashba Spin-Splitting Strength by Orbital Hybridization.

ACS Nano

December 2024

Department of Materials Science and Engineering, National University of Singapore, Singapore117575, Singapore.

A Rashba spin-splitting state with spin-momentum locking enables the charge-spin interconversion known as the Rashba effect, induced by the interplay of inversion symmetry breaking (ISB) and spin-orbit coupling (SOC). Enhancing spin-splitting strength is promising to achieve high spin-orbit torque (SOT) efficiency for low-power-consumption spintronic devices. However, the energy scale of natural ISB at the interface is relatively small, leading to the weak Rashba effect.

View Article and Find Full Text PDF

Spintronic devices and applications using noncollinear chiral antiferromagnets.

Nanoscale Horiz

December 2024

Electrical and Computer Engineering, The Grainger College of Engineering, University of Illinois Urbana-Champaign, Urbana, USA.

Antiferromagnetic materials have several unique properties, such as a vanishingly small net magnetization, which generates weak dipolar fields and makes them robust against perturbation from external magnetic fields and rapid magnetization dynamics, as dictated by the geometric mean of their exchange and anisotropy energies. However, experimental and theoretical techniques to detect and manipulate the antiferromagnetic order in a fully electrical manner must be developed to enable advanced spintronic devices with antiferromagnets as their active spin-dependent elements. Among the various antiferromagnetic materials, conducting antiferromagnets offer high electrical and thermal conductivities and strong electron-spin-phonon interactions.

View Article and Find Full Text PDF

The prevailing research emphasis has been on reducing the critical switching current density (J) by enhancing the damping-like efficiency (β). However, recent studies have shown that the field-like efficiency (β) can also play a major role in reducing J. In this study, the central inversion asymmetry of Pt-Co is significantly enhanced through interface engineering at the sub-atomic layer of Ta, thereby inducing substantial alterations in the β associated with the interface.

View Article and Find Full Text PDF

Manipulating the polarization of spin current is essential for understanding the mechanism of charge-to-spin conversion and achieving efficient electrically driven magnetization switching. Here, a novel exchange-spring magnetic structure is introduced formed by the coupling of perpendicular magnetic anisotropy (PMA) CoTb and in-plane magnetic anisotropy (IMA) Co films. When a spin current with the polarization along the y-direction flows through this exchange-spring (x-z plane) structure, the interaction between the y-spin and the local exchange field with a non-collinear spatial distribution gives rise to substantial unconventional spin polarizations in the x- and z-directions, enabling field-free spin-orbit torque driven perpendicular magnetization switching at room temperature.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!