37 research outputs found
Tailoring the magnetodynamic properties of nanomagnets using magnetocrystalline and shape anisotropies
Magnetodynamical properties of nanomagnets are affected by the demagnetizing
fields created by the same nanoelements. In addition, magnetocrystalline
anisotropy produces an effective field that also contributes to the spin
dynamics. In this article we show how the dimensions of magnetic elements can
be used to balance crystalline and shape anisotropies, and that this can be
used to tailor the magnetodynamic properties. We study ferromagnetic ellipses
patterned from a 10 nm thick epitaxial Fe film with dimensions ranging from 50
x 150 nm to 150 x 450 nm. The study combines ferromagnetic resonance (FMR)
spectroscopy with analytical calculations and micromagnetic simulations, and
proves that the dynamical properties can be effectively controlled by changing
the size of the nanomagnets. We also show how edge defects in the samples
influence the magnetization dynamics. Dynamical edge modes localized along the
sample edges are strongly influenced by edge defects, and this needs to be
taken into account in understanding the full FMR spectrumComment: Accepted for publication in Phys. Rev.