Reduced domain wall pinning in ultrathin Pt/Co100−xBx/Pt with perpendicular magnetic anisotropy

Abstract

We have studied the magnetization reversal process in perpendicularly magnetized ultrathin Pt/Co100−xBx/Pt films by means of magneto-optical magnetometry and microscopy. The addition of boron enhances the effective Barkhausen volume indicating a decrease in domain-wall pinning site density and/or strength. This potentially reduces the field and critical current-density for domain-wall depinning/motion, indicating that perpendicularly magnetized Pt/Co100−xBx/Pt could be an interesting candidate for domain-wall motion studies and applications.

CoB/Ni-Based Multilayer Nanowire with High-Speed Domain Wall Motion under Low Current Control

“…Hence, such decreases in saturation magnetization magnitude and wall width could result in a decrease in the threshold critical current. Moreover, the addition of B atoms on the other hand weakens the pinning of the DW by decreasing the number of pinning sites 25) as mentioned in previous paragraphs. This effect also enhances the velocity of the walls.…”

Reduced stochasticity in domain wall motion with increasing pinning density in thin Fe films

“…, which is generally interpreted as the average distance between DW pinning sites [32,33]. For the films with t Fe = 50 and 60 nm, L A is about (21 ± 2) and (16 ± 1) nm, respectively, using the measured value of M S ∼ 1750 emu cc −1 for these films.…”

Magnetic states in low-pinning high-anisotropy material nanostructures suitable for dynamic imaging

“…30,31 To calculate the crystal field uniaxial anisotropy constant K u , we make use of the analytic relation H = ∂F μ 0 ∂M between the magnetic field H and the magnetization M through the free energy density F , which holds if the system is in thermodynamic equilibrium. 36 In absence of any further knowledge of the magnetization reversal mechanism, the equilibrium magnetization can be approximated by the average of both hysteresis branches, with the difference giving a reasonable estimate for the 2σ confidence interval.…”

“…In this material a significant reduction of the domain wall pinning has been found using quasistatic measurement techniques on films with subnanometer Co thickness. 30,31 For x-ray-transmission-based imaging, however, we need a minimum total thickness of a few nanometers of magnetic material. As the PMA in nonepitaxial Co/Pt arises from the Co/Pt interface interaction, 32 a natural way to retain the magnetic properties in a few nanometers thick configuration is to use multilayer stacks.…”