Abstract

Deterministic current-induced magnetization reversal is observed in quasi-perpendicularly magnetized Ta/Pt/CoFeB/Pt multilayer thin films without the assistance of an in-plane field. In a quasi-perpendicularly magnetized system, the anisotropy is tilted slightly away from the normal to the film plane. This tilt in the anisotropy is obtained by growing the films in an oblique-angle sputter deposition technique, which results in a gradient in the thickness of the layers. To estimate the tilt, out-of-plane hysteresis loop measurements are performed in the presence of an in-plane bias field. The effect of the tilt is reflected in the shift in the hysteresis loop. A measurement of this shift at different relative azimuthal orientations of the in-plane projection of the tilt direction with respect to the in-plane bias field direction gives a tilt of 0.74° (±0.06°) in Ta(3 nm)Pt(3 nm)CoFeB(0.5 nm)Pt(1 nm) with all the layers having a thickness gradient. In addition, field-induced domain wall velocity measurements in the creep regime on Ta(3 nm)Pt(3 nm)CoFeB(0.5 nm)Pt(1 nm) thin film with a thickness gradient only in CoFeB layer give an elliptical profile for the domain wall. In the current-induced magnetization reversal studies, threshold current density of $1.06 \times 10^{11}$ Am−2 is required to deterministically switch the device fabricated from Ta(3 nm)Pt(3 nm)CoFeB(0.5 nm)Pt(1 nm) thin film with all the layers having a thickness gradient. On application of in-plane bias, there is a shift in the threshold current densities given by $2.6 \times 10^{8}$ Am−2 of in-plane bias field.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.