The effect of magnetic anisotropy on the spin configurations of patterned La_0.7Sr_0.3MnO₃elements

Abstract

We study the effect of magnetocrystalline anisotropy on the magnetic configurations of La0.7Sr0.3MnO3 bar and triangle elements using photoemission electron microscopy imaging. The dominant remanent state is a low energy flux-closure state for both thin (15 nm) and thick (50 nm) elements. The magnetocrystalline anisotropy, which competes with the dipolar energy, causes a strong modification of the spin configuration in the thin elements, depending on the shape, size and orientation of the structures. We investigate the magnetic switching processes and observe in triangular shaped elements a displacement of the vortex core along the easy axis for an external magnetic field applied close to the hard axis, which is well reproduced by micromagnetic simulations.

Nanoscale Mapping of the Magnetic Properties of (111)-Oriented La0.67Sr0.33MnO3

“…The volume exchange stiffness, A , is related to the quantum mechanical exchange stiffness, J , in a cubic system by the relation A = JS 2 / a , where S is the spin of the local moments and a is the lattice parameter. This produces an exchange stiffness constant, A ex , of 1.86 pJ/m, which is in good agreement with the literature, which suggests values between 1.7 and 1.5 pJ/m . Measuring the exchange stiffness is not trivial and is typically done through the excitation of spin waves by light, neutrons, or microwaves .…”

“…This produces an exchange stiffness constant, A ex , of 1.86 pJ/m, which is in good agreement with the literature, which suggests values between 1.7 59 and 1.5 pJ/m. 83 Measuring the exchange stiffness is not trivial and is typically done through the excitation of spin waves by light, 84 neutrons, 85 or microwaves. 86 Although the method presented here does not provide a direct measure of A ex , this is an important result, as it demonstrates the feasibility of measuring fundamental material properties using electron microscopy alone.…”

Large magnetoelectric coupling in multiferroic oxide heterostructures assembled via epitaxial lift-off

“…Conformal contact with the surface topography of micron-sized ferroelectric domains yielded structurally contiguous single magnetic domains of strain-released LSMO. These magnetic domains typically spanned a few microns, such that they are larger than the majority of epitaxial magnetic structures defined by lithography [51][52][53] .…”