Encapsulating cage structures, pentagonal dodecahedron, open dodecahedron, and distorted cube of the type-III clathrate compound. The white and black spheres stand for trigonally (Tr) and tertragonally (Tt) bonded framework atoms, respectively.
SEM backscattered electron images of with (a) , (b) , (c) , (d) , (e) , and (f) .
Portions of the ternary phase diagram in the Ba–In–Ge system at . Two different triangles corresponding to the three-phase regions [-I -III clathrate and type-III -I ] are located near the Ge and In corners, respectively. The open circles correspond to the nominal compositions of the specimens used.
Values of (a) electrical resistivity, (b) Seebeck coefficient, and (c) thermoelectric power factor for alloys with plotted as a function of temperature. Data points for the alloy are also plotted for comparison.
(a) Values of thermal conductivity for alloys up to plotted as a function of temperature. Data points for the alloy are also plotted for comparison. (b) Values of electronic and lattice thermal conductivity for alloys at room temperature plotted as a function of In content . Data points similarly calculated for alloys are also plotted.
Dimensionless figure of merit for alloys with plotted as a function of temperature. Data points for the alloy are also plotted for comparison.
Average bond lengths between the Ba guest atoms and encapsulating cage atoms and those between the encapsulating atoms plotted as a function of In content obtained by EDS and Rietveld analyses.
Values of ADP for guest and framework atoms in the type-III clathrate compound, plotted as a function of temperature.
Indium content for the type-III and type-I phases present in the specimens obtained by EDS analyses. In the analyses, all the sites are assumed to be fully occupied.
Results of Rietveld refinement for the type-III clathrate phase in the specimens with . [Atomic positions are ; ; ; ; ; ; ; ; and .]
Einstein temperatures , Debye temperature , and disorder parameters evaluated from the temperature dependence of ADPs for together with corresponding values obtained for .
The average atomic weight of crystal and the average volume occupied by an atom in and .
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