Solid-State Lithium Ion Supercapacitor for Voltage Control of Skyrmions

Abstract

Ionic control of magnetism gives rise to high magnetoelectric coupling efficiencies at low voltages, which is essential for low-power magnetism-based nonconventional computing technologies. However, for on-chip applications, magnetoionic devices typically suffer from slow kinetics, poor cyclability, impractical liquid architectures, or strong ambient effects. As a route to overcoming these problems, we demonstrate a LiPON-based solid-state ionic supercapacitor with a magnetic Pt/Co40Fe40B20/Pt thin-film electrode which enables voltage control of a magnetic skyrmion state. Skyrmion nucleation and annihilation are caused by Li ion accumulation and depletion at the magnetic interface under an applied voltage. The skyrmion density can be controlled through dc applied voltages or through voltage pulses. The skyrmions are nucleated by single 60 μs voltage pulses, and devices are cycled 750000 times without loss of electrical performance. Our results demonstrate a simple and robust approach to ionic control of magnetism in spin-based devices.

Ionic control of magnetism in all-solid-state CoOx/yttria-stabilized zirconia heterostructures

“…Magneto-ionics can cause a large nonvolatile modulation of a variety of magnetic properties, such as coercivity, anisotropy, magnetization, exchange bias, domain wall motion, or skyrmion density, even inducing transitions between paramagnetic and ferromagnetic states in some cases. [1][2][3][4][5][6] Most magneto-ionic studies have focused on the effects of triggering the motion of ions from an ion reservoir (e.g., HfO 2 , 7 GdO x , 8 and liquid electrolyte with Li þ in dissolution 9 ) to an adjacent target magneto-ionic film (typically, a ferromagnetic metal or ferrimagnetic transition metal oxide). In addition, we have shown during the last few years, that it is also possible to induce the appearance of ferromagnetic properties starting from initially paramagnetic films that contain the mobile ions (e.g., O 2À or N 3À ) in their structure.…”