Erratum: Structural Principles and Amorphouslike Thermal Conductivity of Na-Doped Si Clathrates [Phys. Rev. Lett. 85, 114 (2000)]

Raman study of semiconductor clathrates under high pressure

“…The Ba 8 Ge 3 Si 43 clathrate in which Si atoms in 24k sites are partially replaced by Ge atoms, shows phase transition at 16 GPa which is almost the same as that for Ba 8 Si 46 . From comparison of the present results with the previous ones of Ba 8 Si 46 , the 6c site is strongly suggested to be one of the important keys for the phase transition.…”

“…This is likely to be because this band arises from the 16i site of Si [19] which is independent of the substitution. Figure 3 indicates the pressure dependence of Raman spectra of (a) Ba 8 Ge 3 Si 43 , (b) Ba 8 Au 6 Si 40 and (c) Ba 8 Si 46 . As demonstrated in the previous paper [14], the Raman spectrum of Ba 8 Si 46 (Fig.…”

“…Up to now, various types of clathrates have been synthesized with guest atoms of, e.g., alkali, alkaline earth, or halogen, with host atoms of not only Si but also other group IV (Ge, and Sn) or III/V elements, and with different structures of type II and III. This class of compounds are attracting much attention because of remarkable properties in the fields of superconductivity [4][5][6], thermoelectric applications [7,8], and wide-bandgap semiconductors [9,10]. Recently, several authors have reported highpressure investigations on the clathrate compounds [11][12][13][14][15][16][17][18].…”

Raman Scattering of Type-I Clathrate Compounds

“…[1][2][3][4][5][6][7] The performance of the thermoelectric materials can be evaluated by the dimensionless figure of merit ZT = S 2 T /ρ(κ el + κ L ), where T , S, ρ, κ el and κ L are absolute temperature, Seebeck coefficient, electric resistivity, electron thermal conductivity and lattice thermal conductivity, respectively. Type-I clathrates and filled skutterudites, which are the typical cage-structured compounds, have shown the anomalous suppression of κ L .…”

Electronic structure of a thermoelectric material: CsBi4Te6

“…In Fig.1 investigations on Na-doped Si clathrate [12] show that high efficiency thermoelectric materials should have high electronic density of states near the highest occupied levels and free electron like density profile for the empty levels. In this regard, the CsBi 4 Te 6 , as shown in Fig.2 In Fig.3, we show our calculated dielectric function ( 2 ) along three different directions,…”