Graduate Seminar Analysis

 

Tuesday Apr 15, 2014, 03.00 pm

Reduced models for domain walls in soft ferromagnetic films

Lukas Doering (MPI Leipzig)

Time: 03:00 pm

Abstract:
Depending on material parameters and sample dimensions, soft ferromagnetic
films exhibit various kinds of domain walls (transition layers between neighboring
domains of constant magnetization).

In the first part of the talk, we present a reduced model for a single domain wall at the
cross-over from symmetric to asymmetric wall types in an infinitely extended film. The
reduced model captures the optimal splitting of the wall into an asymmetric, stray-field
free core and logarithmically decaying, symmetric wall tails (obtained via Gamma convergence,
joint work with R. Ignat and F. Otto).

In the second part, we consider periodic domain patterns for which the wall width is not
only confined by material anisotropy but also the neighboring wall tails. Using methods
similar to the single-wall case, we derive a reduced model that describes the influence of
the tail interaction on the splitting into the core and tails. Moreover, it yields a prediction
for the increased rotation of the magnetization towards magnetic fields applied along the
wall normal direction.

Location: Seminargebäude, Room SG 11, Wüllnerstraße 5 b, 52062 Aachen