Reduction of intrinsic critical current density for current-induced domain wall motion by using a ferrimagnetic nanowire with perpendicular magnetic anisotropy

Abstract

We herein discuss the use of a ferrimagnetic nanowire for current-induced domain wall motion in order to satisfy both high perpendicular anisotropy and low saturation magnetization. We demonstrate the current-induced domain wall motion in magnetic nanowires with various saturation magnetizations by using micromagnetic and analytical calculations. The intrinsic critical current velocity was reduced with decrease of saturation magnetization even if the domain wall width was almost constant, and the intrinsic critical current velocity also can be reduced with the optimum wire width. A significant reduction of critical current density can be obtained by decreasing the saturation magnetization even if the spin polarization of ferrimagnetic materials is below 0.1 because the decrease in the hard-axis anisotropy is dominant for current-induced wall motion.

Manipulation of multiple 360o domain wall structures and its current-driven motion in a magnetic nanostripe

“…2 In recent years, the motion of single domain wall (DW) due to a spin transfer torque of electrons has been well studied theoretically [3][4][5][6] and experimentally. [7][8][9][10][11] For instance, it was known that the velocity of DW increases linearly with the increasing of the applied current, and when the applied current is higher than a critical value, a dramatic reduction in DW average velocity occurs due to Walker breakdown.…”

Effect of a Pinning Field on the Critical Current Density for Current-Induced Domain Wall Motion in Perpendicular Magnetic Anisotropy Nanowires

“…Moreover, Komine et al reported that nanowires with a low saturation magnetization can significantly reduce the intrinsic critical current density. 7 However, domain wall motion is impeded by edge roughness and anisotropy dispersion in actual nanowires, and the influence of the pinning field on the critical current density in nanowires with a low saturation magnetization is not yet well understood. In this study, the influence of the pinning field on the critical current density for CIDWM in low magnetization nanowires was analyzed using micromagnetic simulations.…”

“…There have been numerous reports of current-induced domain wall motion (CIDWM) in nanowires, [1][2][3][4][5][6][7][8][9][10][11][12][13] and spintronics devices based on this principle have been proposed. 2 In order to realize such devices, it is necessary to reduce the critical current density required to move the domain walls in the nanowires.…”

Generation and manipulation of domain walls using a thermal gradient in a ferrimagnetic TbCo wire

“…Hrabec et al have shown that using a composition gradient it is possible to generate a DW in GdCo ferrimagnetic alloys, under a magnetic field, in the vicinity of the compensation composition. 13 Ferrimagnetic alloy materials are studied recently because of their suitability for optical switching, 7,8 positive and negative exchange bias, 14,15 negative GMR effects, 16,17 efficient current induced domain wall motion, 18 and tunable Curie temperature. 19 In this letter, we examine how we can nucleate, propagate, and then annihilate DWs 20,21 in a ferrimagnetic Tb 22 Co 78 via a thermal gradient under applied magnetic fields.…”