  The ability to experimentally map the three-dimensional structure and
dynamics in bulk and patterned three-dimensional ferromagnets is essential both
for understanding fundamental micromagnetic processes, as well as for
investigating technologically-relevant micromagnets whose functions are
connected to the presence and dynamics of fundamental micromagnetic structures,
such as domain walls and vortices. Here, we demonstrate time-resolved magnetic
laminography, a technique which offers access to the temporal evolution of a
complex three-dimensional magnetic structure with nanoscale resolution. We
image the dynamics of the complex three-dimensional magnetization state in a
two-phase bulk magnet with a lateral spatial resolution of 50 nm, mapping the
transition between domain wall precession and the dynamics of a uniform
magnetic domain that is attributed to variations in the magnetization state
across the phase boundary. The capability to probe three-dimensional magnetic
structures with temporal resolution paves the way for the experimental
investigation of novel functionalities arising from dynamic phenomena in bulk
and three-dimensional patterned nanomagnets.
