Fig. 1: Calculated phonon transport properties of BiCuSeO and BiAgSeO.

a Temperature-dependent average thermal conductivity, compared to previous measurement15,20. RTA stands for the relaxation time approximation. Vertical lines are the absolute error obtained by the measurement with the uncertainty of 10% for BiCuSeO15 and the diffusivity uncertainty of 5% for BiAgSeO20 (the density uncertainty was corrected). b Normalized cumulative thermal conductivity along the a-axis. (c, d) are the comparison of the normalized phonon dispersion and the relaxation time, respectively.