TY  - JOUR
AU  - Andreas, Christian
AU  - Gliga, Sebastian
AU  - Hertel, Riccardo
TI  - Numerical micromagnetism of strong inhomogeneities
JO  - Journal of magnetism and magnetic materials
VL  - 362
SN  - 0304-8853
CY  - Amsterdam
PB  - North-Holland Publ. Co.
M1  - FZJ-2015-04169
SP  - 7 - 13
PY  - 2014
AB  - The size of micromagnetic structures, such as domain walls or vortices, is comparable to the exchange length of the ferromagnet. Both, the exchange length of the stray field ls and the magnetocrystalline exchange length lk, are material-dependent quantities that usually lie in the nanometer range. This emphasizes the theoretical challenges associated with the mesoscopic nature of micromagnetism: the magnetic structures are much larger than the atomic lattice constant, but at the same time much smaller than the sample size. In computer simulations, the smallest exchange length serves as an estimate for the largest cell size admissible to prevent appreciable discretization errors. This general rule is not valid in special situations where the magnetization becomes particularly inhomogeneous. When such strongly inhomogeneous structures develop, micromagnetic simulations inevitably contain systematic and numerical errors. It is suggested to combine micromagnetic theory with a Heisenberg model to resolve such problems. We analyze cases where strongly inhomogeneous structures pose limits to standard micromagnetic simulations, arising from fundamental aspects as well as from numerical drawbacks.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000334764500002
DO  - DOI:10.1016/j.jmmm.2014.02.097
UR  - https://juser.fz-juelich.de/record/201875
ER  -