Magneto‐Ionics in Annealed W/CoFeB/HfO₂ Thin Films

Abstract

The magneto‐ionic modulation of the Dzyaloshinskii–Moriya interaction (DMI) and the perpendicular magnetic anisotropy (PMA), in W/CoFeB/HfO2 stacks annealed at different temperatures and for varying annealing times, are presented in this work. A large modulation of PMA and DMI is observed in the systems annealed at 390 and 350 °C, whereas no response to voltage is observed in the as‐grown samples. A strong DMI is only observed in the samples annealed at 390 °C for 1 h, while PMA is present for all annealing times at temperatures of 390 and 350 °C. Magnetic properties including domain wall velocity improve drastically with increasing the annealing temperature and time, while the magneto‐ionic reversibility is increasingly compromised. The changes in PMA and DMI induced by the gate voltages in the samples annealed at 390 °C are permanent, while partial reversibility is only observed for the samples annealed at 350 °C for short times. This dependence of reversibility on post‐grown annealing has been associated to the influence of crystallization on ion mobility. These results show that a compromise between the enhancement of the magnetic properties and the magneto‐ionic performance could be needed in systems requiring annealing to develop PMA and DMI.

Controlling interface anisotropy in CoFeB/MgO/HfO2 using dusting layers and magneto-ionic gating

“…Electric field control of magnetism in nanostructured systems constitutes a solid route towards reducing power consumption in novel memory architectures. Both electrostatic and magneto-ionic effects have shown to greatly modify parameters like the magnetic anisotropy and the Dzyaloshinskii-Moriya interaction (DMI) leading to a very efficient control of domain wall dynamics and skyrmion motion [1][2][3][4][5][6][7][8] . Magneto-ionics is particularly attractive for low-power applications since it provides non-volatile changes in the magnetic states unlike charge effects, which need the constant application of a gate voltage.…”

Recent Advanced Applications of Ionic Liquid for Future Iontronics

“…As a result, the density of the electrically induced charge carriers reaches as large as 10 14 cm −2 or above by applying no more than several volts of the gate voltage V G [13–19] . Such a high carrier accumulation ability has enabled us to perform the field effect control of electronic phases such as Mott insulators, [20,21] superconductivity, [22–24] and ferromagnetism [25–29] . This fundings lead to the new functional devices utilizing ions such as sensors [30–36] and actuators [37–41] …”

“…[13][14][15][16][17][18][19] Such a high carrier accumulation ability has enabled us to perform the field effect control of electronic phases such as Mott insulators, [20,21] superconductivity, [22][23][24] and ferromagnetism. [25][26][27][28][29] This fundings lead to the new functional devices utilizing ions such as sensors [30][31][32][33][34][35][36] and actuators. [37][38][39][40][41] What is the best electrolyte for the operation of an EDLT?…”

Spintronic Heterostructures for Artificial Intelligence: A Materials Perspective

“…[92,93] Several other efforts were made to improve the spin-Hall torque efficiency in the W and SHA in a range from %0.15 to %0.65. [81,[94][95][96][97][98][99][100][101][102][103][104][105][106] However, the problem with Ta and W is the high resistivity (generally, in the excess of %200 μΩ cm), which may not be desired for energy-efficient DW motion/magnetization switching. Other than attractive Pt, Ta, and W, several other 4d and 5d materials were studied.…”