Spin Orientation Manipulation by Electric Fields and X-ray Irradiation

Mariia Filianina, Weiliang Gan, Tetsuya Hajiri, Michael Le, Tatiana Savchenko, Sergio Valencia, Mohamad-Assaad Mawass, Florian Kronast, Samridh Jaiswal, Gerhard Jakob, and Mathias Kläui

Electric field-induced strain engineering of the magnetic anisotropy offers a highlyattractive perspective for designing future generations of energy-efficient informationtechnologies. In this work, we show using x-ray magnetic imaging and magneto-optic Kerr effect that the applicability of this approach is limited to systems withcomparably low magnetic anisotropies or sufficiently large magnetostrictive effect.Furthermore, we find that long x-ray exposure leads to an irreversible change of themagnetic anisotropy in thin ferromagnetic CoFeB films so caution needs to be ex-ercised when analyzing anisotropies. While this change of the anisotropy is shownto be beneficial for the strain-induced manipulation of the magnetic structure, themechanisms underlying the observed x-ray induced transformation remain an openquestion. Finally, by directly imaging the magnetic domain structure with graduallyvarying anisotropy from out-of-plane to in-plane, we observe the impact of strainacross the spin-reorientation transition.