Estimating carrier relaxation times in the Ba ₈ Ga ₁₆ Ge ₃₀ clathrate in the extrinsic regime

), while in polycrystalline materials scattering at grain boundaries dominates (τ ∼ cte). The Seebeck coefficient, electrical conductivity, and electron heat conduction are in consistent agreement with experiment. Furthermore, the Slack relation for lattice heat conductivity was successfully applied to the material. The calculated figure of merit is in good agreement with experimental results.