Effect of Device Temperature on Domain Wall Motion in a Perpendicularly Magnetized Co/Ni Wire

Abstract

This paper describes experimental results obtained from measuring the dependence of device temperature on the current for domain wall motion in a Co/Ni wire having perpendicular magnetic anisotropy. Devices with different insulating layer thicknesses were prepared in order to control the device temperature. A stable domain wall motion was observed up to the temperature at which perpendicular magnetic anisotropy vanishes. Moreover, the current required for domain wall motion was independent of the device temperature.

Magnetic field insensitivity of magnetic domain wall velocity induced by electrical current in Co/Ni nanowire

“…Saturation of v observed at higher current densities are most likely due to the wire temperature being increased by Joule heating. [21][22][23] The red solid line in Fig. 3 is a tangential line to the experimental results at 0 Oe.…”

Depinning probability of a magnetic domain wall in nanowires by spin-polarized currents

“…For DW depinning experiments, a perpendicularly magnetized Co/Ni multilayer 18 deposited onto a Si substrate was used. This is a promising material for application to DW-motion devices because of several features in terms of stable operation and retention characteristics [21][22][23] , owing to its nature that the DW can be driven by an adiabatic STT 22 . By measuring the magnetization curves of the blanket film along the in-plane and out-of-plane directions, the saturation magnetization M s , perpendicular anisotropy constant and coercive field were obtained to be 0.96 T, 6.1 Â 10 5 J m À 3 , and 16.5 mT, respectively, which are consistent with the values reported in previous works [21][22][23][24] .…”

“…There are mainly two ways to utilize the STT: one is current-induced magnetization switching (CIMS) in magnetic nanopillars 2,[7][8][9][10][11][12] , and the other is current-induced domain wall motion (CIDWM) in magnetic nanowires 1,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] . In particular, the latter is promising for applications in which a domain wall (DW) moves numerous times within several nanoseconds' duration 4 , or in which numerous DWs are shifted simultaneously 6 .…”

Domain-wall free energy in Heisenberg ferromagnets

“…Due to its close relation with chirality, we believe that reconsidering adiabatic STT in the perspective of shortrange chiral order may contribute to shed some light on the puzzling scenario of DW motion induced by electric currents. For instance, adiabatic STT seems to catch the main physics of Co/Ni nanowires magnetized out of plane 83,84 , while it largely fails for prototypical Permalloy nanowires (magnetized in plane) [85][86][87] ; the critical current for DW motion is observed to depend strongly on temperature 88,89 in some samples and not in others 90 .…”