Optical Thermal Diffusivity Measurements in PdxErTe3

PdxErTe3 is a quasi-2D metal with two stripe ordered charge density wave (CDW) orders with of Pd intercalated between the ErTe3 layers [1]. Increasing Pd intercalation increases disorder and suppresses the CDW transitions [1,2]. We use a photo-thermal microscope for high resolution thermal diffusivity and optical reflectivity measurements by measuring phase delay in local reflectivity. This is supplemented with resistivity and thermopower measurements. Our primary observation is a decrease of thermal diffusivity and the onset of anisotropy in all transport channels below the higher temperature CDW transition. We will further discuss the relation between thermal and charge transport, and the applicability of Wiedemann-Franz law through the two CDW transitions.


[1] J. A. W. Straquadine, et al., Phys. Rev. B 99, 235138 (2019).
[2] A.Fang, et al., arXiv:1901.03471 [cond-mat.str-el].