SW excitation from pinned magnetic DWs

Tunable short-wavelength spin wave excitation from pinned magnetic domain walls.
Ben van de Viele, Sampo J. Hämäläinen, Pavel Baláž, Federico Montoncello & Sebastiaan van Dijken
Scientific Reports 6, 21330 (2016)

(a) Schematic of the ferroelectric-ferromagnetic bilayer structure. The polarization of the ferroelectric a1 and a2 domains is aligned along the elongated in-plane axis of the tetragonal BaTiO3 lattice and it rotates by 90 degrees at the domain boundaries. Via strain transfer and inverse magnetostriction, uniaxial anisotropy is induced in the ferromagnetic layer. The resulting ferromagnetic domain pattern fully correlates with the ferroelectric domain structure and magnetic domain walls are strongly pinned onto the ferroelectric domain boundaries by abrupt 90 degree rotations of magnetic anisotropy. (b) Micromagnetic simulation geometry for an extended film. The computational area is restricted to one period of the stripe domain structure, i.e. a single a1 and a2 domain, both having a width of 3.2 μm. Periodic boundary conditions in the x- and y-direction are used to account for the continuous film geometry. The simulated magnetization pattern near the magnetic domain wall is shown as inset.