Kadowaki-Woods relation and thermal transport in the two-dimensional van der Waals ferromagnet Fe3GeTe2

We have studied electric and thermal transport properties in two-dimensional van der Waals ferromagnetic Fe3GeTe2. The low-temperature longitudinal resistivity measured in the ab plane is contributed by the impurity scattering, the quantum correction, and the electron-electron interaction. Meanwhile, the low-temperature specific heat consists of linear and cubic temperature terms, corresponding to contributions of electrons and phonons, respectively. Therefore, the heavy-fermion state in Fe3GeTe2 can be described by Landau's Fermi liquid theory. The Kadowaki-Woods ratio in Fe3GeTe2 is five times larger and smaller than the values of transition metals and heavy-fermion compounds, respectively. Moreover, the thermal conductivity measured along the c axis increases monotonically with temperature, exhibiting a phonon glass electron crystal behavior, due to the dominant role of boundary scattering of phonons. The T1.35 dependence of the lattice thermal conductivity observed at low temperatures arises from a combined effect of the highly anisotropic dispersion and strong impurity scattering of phonons.

Automated summary

We have investigated the electric and thermal transport properties of two-dimensional van der Waals ferromagnetic Fe3GeTe2. The low-temperature longitudinal resistivity in the ab plane is influenced by impurity scattering, quantum correction, and electron-electron interaction. The low-temperature specific heat consists of linear and cubic temperature terms, corresponding to contributions from electrons and phonons. The heavy-fermion state in Fe3GeTe2 can be described by Landau's Fermi liquid theory. The Kadowaki-Woods ratio in Fe3GeTe2 is five times larger and smaller than that of transition metals and heavy-fermion compounds, respectively. Moreover, the thermal conductivity along the c axis increases monotonically with temperature, exhibiting a phonon glass electron crystal behavior due to boundary scattering of phonons. The observed T1.35 dependence of the lattice thermal conductivity at low temperatures arises from the combined effect of highly anisotropic dispersion and strong impurity scattering of phonons.