Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 15, 2008 | Supplemental Material
Journal Article Open

Synthesis, structure, and high-temperature thermoelectric properties of boron-doped Ba_8Al_(14)Si_(31) clathrate I phases

Abstract

Single crystals of boron-doped Ba_8Al_(14)Si_(31) clathrate I phase were prepared using Al flux growth. The structure and elemental composition of the samples were characterized by single-crystal and powder X-ray diffraction; elemental analysis; and multinuclear ^(27)Al, ^(11)B, and ^(29)Si solid-state NMR. The samples' compositions of Ba_8B_(0.17)Al_(14)Si_(31), Ba_8B_(0.19)Al_(15)Si_(31), and Ba_8B_(0.32)Al_(14)Si_(310) were consistent with the framework-deficient clathrate I structure Ba_8Al_xSi_(42-3/4x)□_(4-1/4x) (X = 14, □ = lattice defect). Solid-state NMR provides further evidence for boron doped into the framework structure. Temperature-dependent resistivity indicates metallic behavior, and the negative Seebeck coefficient indicates that transport processes are dominated by electrons. Thermal conductivity is low, but not significantly lower than that observed in the undoped Ba_8Al_(14)Si_(31) prepared in the same manner.

Additional Information

© 2008 American Chemical Society. Publication Date (Web): August 19, 2008. The authors gratefully acknowledge Dr. Alexandra Navrotsky (Department of Chemistry and Thermochemistry Facility and NEAT ORU, University of California Davis) for use of the Scintag powder diffractometer. This work was supported by the National Science Foundation (Grant DMR-0600742). C.L.C. acknowledges a Tyco Electronics Foundation Fellowship in functional materials. Portions of this work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. P.J. acknowledges financial support by the Alexander von Humboldt foundation.

Attached Files

Supplemental Material - ic800772m_si_001.pdf?cookieSet=1

Files

ic800772m_si_001.pdf
Files (427.0 kB)
Name Size Download all
md5:ca913b18560dd0abda669cd64b1058cd
427.0 kB Preview Download

Additional details

Created:
September 15, 2023
Modified:
October 23, 2023