Modelling of the Dynamical Fluorescent Micro-Thermal Imaging Experiment on the Heat Diffusion in the La5Ca9Cu24O41 Spin Ladder Compound

E. Khadikova[1], F. de Haan[1], P. H. M. van Loosdrecht[2]
[1]Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
[2]Department of Physics, University of Cologne, Köln, Germany
Published in 2014

The dynamical fluorescent micro-thermal 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 carried by magnetic excitations (magnons). To extract information on the phonon-magnon interaction we modelled the dynamic heat transport experiment using a two temperature model approach and taking both the crystal as well as the europium (III) thenoyltrifluoroacetonate / deuterated Poly(methyl methacrylate) fluorescent heat imaging layer into account. The simulations are carried out by the finite element method using COMSOL Multiphysics® with the Heat Transfer Module. The results of the numerical calculations are crucial to the data analysis of the experimental studies.