  Voltage control of interfacial magnetism has been greatly highlighted in
spintronics research for many years, as it might enable ultra-low power
technologies. Among few suggested approaches, magneto-ionic control of
magnetism has demonstrated large modulation of magnetic anisotropy. Moreover,
the recent demonstration of magneto-ionic devices using hydrogen ions presented
relatively fast magnetization toggle switching, tsw ~ 100 ms, at room
temperature. However, the operation speed may need to be significantly improved
to be used for modern electronic devices. Here, we demonstrate that the speed
of proton-induced magnetization toggle switching largely depends on
proton-conducting oxides. We achieve ~1 ms reliable (> 103 cycles) switching
using yttria-stabilized zirconia (YSZ), which is ~ 100 times faster than the
state-of-the-art magneto-ionic devices reported to date at room temperature.
Our results suggest further engineering of the proton-conducting materials
could bring substantial improvement that may enable new low-power computing
scheme based on magneto-ionics.
