Title:
Fast switching of nanomagnets: A micromagnetic study
Author: Josef Fidler
Vienna University of Technology, Austria.
Magnetics Society Distinguished Lecture.
Abstract:
Switching of small particles, thin film elements and nano-wires becomes
increasingly important in magnetic storage and magnetoelectronic
devices. The magnetization reversal processes are studied using a 3D
hybrid finite element/boundary element micromagnetic model. Transient
magnetization states during switching are investigated numerically in
thin NiFe, Fe and Co nano-elements of various shapes. Switching dynamics
are calculated for different external field profiles and frequencies.
The numerical solution of Brown's equations can be effectively performed
using finite-element and related methods that easily handle complex
microstructures and take into account the long-range magnetostatic
interactions and short-range exchange coupling between the grains in
granular thin films. Dynamic finite-element simulations successfully predict
the influence of microstructural features like grain size, particle shape,
intergranular phases, and surface irregularities on the magnetic properties.
Theoretical limits for remanence, coercive field, switching behavior at
a short time scale, and other properties have successfully been calculated.