Enhancement of perpendicular magnetic anisotropy and Dzyaloshinskii–Moriya interaction in thin ferromagnetic films by atomic-scale modulation of interfaces

Abstract

To stabilize nontrivial spin textures, e.g., skyrmions or chiral domain walls in ultrathin magnetic films, an additional degree of freedom, such as the interfacial Dzyaloshinskii-Moriya interaction (IDMI), must be induced by the strong spin-orbit coupling (SOC) of a stacked heavy metal layer. However, advanced approaches to simultaneously control the IDMI and perpendicular magnetic anisotropy (PMA) are needed for future spin-orbitronic device implementations. Here, we show the effect of atomic-scale surface modulation on the magnetic properties and IDMI in ultrathin films composed of 5d heavy metal/ferromagnet/4d(5d) heavy metal or oxide interfaces, such as Pt/CoFeSiB/Ru, Pt/CoFeSiB/ Ta, and Pt/CoFeSiB/MgO. The maximum IDMI value corresponds to the correlated roughness of the bottom and top interfaces of the ferromagnetic layer. The proposed approach for significant enhancement of PMA and the IDMI through interface roughness engineering at the atomic scale offers a powerful tool for the development of spinorbitronic devices with precise and reliable controllability of their functionality.

Бистабильность Магнитных Скирмионов В Многослойной Структуре Ферромагнетик/Тяжелый Металл

“…Микромагнитное моделирование проводилось в программном пакете MuMax3 [15], в котором решается уравнение Ландау−Лифшица−Гильберта [16] личина взаимодействия DMI изменялась в диапазоне 0−1.2 mJ/m 2 , что согласуется с экспериментальными данными [6,[17][18][19][20][21].…”

Inducing Dzyaloshinskii–Moriya interaction in symmetrical multilayers using post annealing

“…They found that the net iDMI increases as the difference between the interface quality of the top and bottom Co layer increases. In addition, Samardak et al 14 studied the effect of atomic-scale surface modulation on the iDMI in ultrathin films composed of 5d heavy metal/ferromagnet/4d (5d) heavy metal or oxide interface. They predicted that a significant enhancement of the iDMI by up to 2.5 times can be achieved through interface roughness engineering on the atomic scale.…”

XMCD and ab initio study of interface-engineered ultrathin Ru/Co/W/Ru films with perpendicular magnetic anisotropy and strong Dzyaloshinskii–Moriya interaction

“…13 The primary consideration in this field is related to ideal structural interfaces. Little attention has been paid to the disordered structure of thin films, 14,15 where the layers have surface roughness and undergo intermixing at the interfaces. Furthermore, theoretically and experimentally, it was demonstrated that the atomically intermixed ''ferromagnetic/heavy metal'' (FM/HM) interfaces could induce an extrinsic SOC, which enhances the spinorbit torque (SOT).…”