Fig.1

(a) Temperature dependence of the lattice thermal conductivity for Cu2-xSe[11] and (b) number of atoms in the primitive unit cell versus room temperature lattice thermal conductivity[12,13,14,15,16] "

Fig. 2

(a) Schematic diagram of crystal structure for Ba8Ga16Ge30, (b) a simple spring model and (c) the corresponding dispersion relation of filled and unfilled clathrate[29]describing interaction between the host cages with a spring constant K1 and the guest atoms attached to the cages with a spring constant K2 "

Fig. 3

Grüneisen parameter versus room temperature lattice thermal conductivity[6, 22, 39-53] "

Fig.4

(a) Phonon frequency dependence of spectral lattice thermal conductivity for (Nb0.6Ta0.4)0.8Ti0.2FeSb and Nb0.8Ti0.2FeSb, and (b) relationship between Ta content and lattice thermal conductivity/disorder parameter for (Nb0.6Ta0.4)0.8Ti0.2FeSb[70] "

Fig. 5

(a) Inverse FFT images and strain mapping of dislocations in the Mg2Si0.5Sb0.5, and (b) lattice thermal conductivity comparison between Mg2Si1-xSbx and Mg2Si1-zSnz at room temperature[84] "

Fig. 6

(a) Schematic diagram of crystal structure for BiSe and (b) lattice thermal conductivity comparison between Bi2Se3 and BiSe[88] "

Fig. 7

(a) Schematic diagram of electron-phonon scattering and (b) comparison of experimental and calculated lattice thermal conductivities by Callaway Model for the silicon sample[93] "

Fig. 8

(a) Schematic diagram of the difference between diffusion model and phonon model, and (b) comparison of calculated minimum lattice thermal conductivities by Cahill model and diffuson model "

Fig. 9

Several strategies to obtain low lattice thermal conductivity "