Effect of annealing on the interfacial Dzyaloshinskii-Moriya interaction in Ta/CoFeB/MgO trilayers

Abstract

The interfacial Dzyaloshinskii-Moriya interaction (DMI) has been shown to stabilize homochiral Néel-type domain walls in thin films with perpendicular magnetic anisotropy and as a result permit them to be propagated by a spin Hall torque. In this study, we demonstrate that in Ta/Co 20 Fe 60 B 20 /MgO the DMI may be influenced by annealing. We find that the DMI peaks at D = 0.057 ± 0.003 mJ/m 2 at an annealing temperature of 230 • C. DMI fields were measured using a purely field-driven creep regime domain expansion technique. The DMI field and the anisotropy field follow a similar trend as a function of annealing temperature. We infer that the behavior of the DMI and the anisotropy are related to interfacial crystal ordering and B expulsion out of the CoFeB layer as the annealing temperature is increased.

Individual skyrmion manipulation by local magnetic field gradients

“…Multilayer M s (A/m) K eff (J/m 3 The magnitude of D s extracted for Ta/CoFeB/MgO and W/CoFeB/MgO multilayers is in line with values reported for similar systems, in experiments that quantify the DMI through current-driven or field-driven domain wall motion, as well as from measurements of equilibrium domain patterns 26,[34][35][36] . On the other hand, lower estimations of D s in these systems have been extracted through Brillouin Light Scattering (BLS) measurements 37,38 .…”

Magnetic properties, domain-wall creep motion, and the Dzyaloshinskii-Moriya interaction in Pt/Co/Ir thin films

“…The model was shown to work well for the Pt/Co/Pt films studied by Je et al [7], and also well for the Ta/CoFeB/MgO studied by Khan et al [13]. Lavrijsen et al [12] find a wide variety of v(H x ) curves for Pt/Co/Pt that are not symmetric around the minimum velocity.…”

“…The DM field in Pt/Co/Ir was measured by expanding a reverse domain in the creep regime, as first proposed by Je et al [7] and subsequently employed by a number of investigators for a range of magnetic thin films [9,[12][13][14][15]23]. The model describing the domain expansion is a version of the creep law with the energy barrier scaling parameter modified to include the change to the domain-wall energy due to an applied inplane bias field.…”

“…The interfacial DM interaction has attracted much interest [5,8,9,[11][12][13][14][15] and has been investigated using different techniques [5,7,[15][16][17][18]. A commonly used method, particularly for ultrathin trilayer films with perpendicular magnetic anisotropy, is the expansion of reverse domains in the creep regime under in-plane bias fields, introduced by Je et al [7].…”

“…A commonly used method, particularly for ultrathin trilayer films with perpendicular magnetic anisotropy, is the expansion of reverse domains in the creep regime under in-plane bias fields, introduced by Je et al [7]. This method has been applied in a range of cases, sometimes giving results that fit well to the modified creep model [7,13,14], sometimes giving results that are more difficult to interpret [12,15,16] or that do not give the same value for the DM energy as other methods [16]. Where it fits well to experimental data and gives a clear result, the creep model can provide a value for the DM energy over a localized area (for example, close to a defect acting as a nucleation center) in which other phenomena are being observed, or provide a lower limit for a thin film [18].…”