  The dynamical fluorescent microthermal imaging (FMI) experiment has been used
to investigate the phonon-magnon interaction in the 1D Heisenberg
antiferromagnet La5Ca9Cu24O41. This material shows highly anisotropic heat
conductivity due to the efficient magnetic heat transport along the spin
ladders in the compound. To extract information on the phonon-magnon
interaction we modelled the dynamic heat transport experiment using a two
temperature model approach, taking both the crystal as well as the PMMA/EuTTA
fluorescent heat imaging layer into account. The simulations are carried out by
the finite element method using COMSOL Multiphysics Heat Transfer Module. The
results of the numerical calculations are expected to be used for the data
analysis of the experimental studies.
