Control of the magnetic anisotropy in multi-repeat Pt/Co/Al heterostructures using magneto-ionic gating
cond-mat.mtrl-sci
/ Authors
Tristan da Câmara Santa Clara Gomes, Tanvi Bhatnagar-Schöffmann, Sachin Krishnia, Yanis Sassi, Dedalo Sanz-Hernández, Nicolas Reyren, Marie-Blandine Martin, Frederic Brunnett, Sophie Collin, Florian Godel
and 7 more authors
Shimpei Ono, Damien Querlioz, Dafiné Ravelosona, Vincent Cros, Julie Grollier, Pierre Seneor, Liza Herrera Diez
/ Abstract
Controlling magnetic properties through the application of an electric field is a significant challenge in modern nanomagnetism. In this study, we investigate the magneto-ionic control of magnetic anisotropy in the topmost Co layer in Ta/Pt/[Co/Al/Pt]$_n$/Co/Al/AlO$_\text{x}$ multilayer stacks comprising $n +1$ Co layers and its impact on the magnetic properties of the multilayers. We demonstrate that the perpendicular magnetic anisotropy can be reversibly quenched through gate-driven oxidation of the intermediary Al layer between Co and AlO$_\text{x}$, enabling dynamic control of the magnetic layers contributing to the out-of-plane remanence - varying between $n$ and $n +1$. For multilayer configurations with $n = 2$ and $n = 4$, we observe reversible and non-volatile additions of 1/3 and 1/5, respectively, to the anomalous Hall effect amplitude based on the applied gate voltage. Magnetic imaging reveals that the gate-induced spin-reorientation transition occurs through the propagation of a single 90$^{\circ}$ magnetic domain wall separating the perpendicular and in-plane anisotropy states. In the 5-repetition multilayer, the modification leads to a doubling of the period of the magnetic domains at remanence. These results demonstrate that the magneto-ionic control of the anisotropy of a single magnetic layer can be used to control the magnetic properties of coupled multilayer systems, extending beyond the gating effects on a single magnetic layer.