1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Synthesis and thermoelectric properties of type-VIII germanium clathrates
Rent:
Rent this article for
USD
10.1063/1.3100205
/content/aip/journal/jap/105/7/10.1063/1.3100205
http://aip.metastore.ingenta.com/content/aip/journal/jap/105/7/10.1063/1.3100205

Figures

Image of FIG. 1.
FIG. 1.

XRD patterns of the nominal clathrates. The lower two patterns are simulated ones of the type-VIII and type-I clathrates, and the open and closed triangles indicate some peak positions of and Ge, respectively.

Image of FIG. 2.
FIG. 2.

Temperature dependences of the electrical conductivity for the type-VIII clathrates. The data of the type-I clathrate are plotted for comparison (Ref. 7). The dotted line is a fit to .

Image of FIG. 3.
FIG. 3.

Temperature dependences of the Seebeck coefficient for the type-VIII clathrates. The data of the type-I clathrate are plotted for comparison (Ref. 7). The thin solid curves also indicate the calculated values for type samples having the temperature-independent effective masses of , , and along with a carrier concentration of .

Image of FIG. 4.
FIG. 4.

Temperature dependences of the lattice thermal conductivity for the type-VIII clathrates. The data of the type-I clathrate are plotted for comparison (Ref. 7). The solid curves are fits to , where and are constant. The dotted curve indicates the theoretical minimum value of thermal conductivity for Ge.

Image of FIG. 5.
FIG. 5.

Temperature dependences of the dimensionless figure-of-merit for the type-VIII and type-I clathrates (Ref. 7).

Image of FIG. 6.
FIG. 6.

vs for the type-VIII and type-I clathrates. The thick dotted and solid curves are fits to the data of the type-I and type-VIII clathrates, respectively. Inverse value is given by the summation of inverse and inverse , where is independent of and is in inverse proportion to . The data of the type-I and type-VIII clathrates are also plotted with the open and closed triangles, respectively, for comparison (Ref. 16).

Image of FIG. 7.
FIG. 7.

The effective masses and the Hall mobilities vs the carrier concentrations for the type-VIII , the type-I (Ref. 7), the type-VIII (Ref. 16), and the type-I (Ref. 16) clathrates.

Image of FIG. 8.
FIG. 8.

The Seebeck coefficients vs the carrier concentrations at RT for the type-VIII and type-I clathrates. Those for the type-VIII and type-I clathrates are plotted for comparison (Ref. 16). The thick solid and dotted curves represent the relations simulated by bandstructure calculation for the type-VIII and type-I clathrates, respectively, where the curves M are from Ref. 18 and the curve B is from Ref. 28. The thin curves represent the relations calculated for samples with and and .

Tables

Generic image for table
Table I.

RT primary properties for some type-VIII samples and the type-I sample: , carrier concentration; , effective mass; , Hall mobility; , lattice thermal conductivity; and , materials factor.

Generic image for table
Table II.

Structural parameters for the sample refined by the Rietveld method [No. 217, , ], where the atom , and the isotropic atomic displacement parameters of and Al, respectively, were set to be equal at the , , , and sites. Goodness of fit: ; and . The sample included Ge of .

Generic image for table
Table III.

Structural parameters for the sample refined by the Rietveld method [No. 223, , ], where the atom . Goodness of fit: ; and .

Loading

Article metrics loading...

/content/aip/journal/jap/105/7/10.1063/1.3100205
2009-04-01
2014-04-18
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Synthesis and thermoelectric properties of type-VIII germanium clathrates Sr8AlxGayGe46−x−y
http://aip.metastore.ingenta.com/content/aip/journal/jap/105/7/10.1063/1.3100205
10.1063/1.3100205
SEARCH_EXPAND_ITEM