Work at the X10c beamline at NSLS was supported by the Division of Materials Sciences of the US Department of Energy (DE-AC02-98CH10886). B.B.I. and A.E.C.P. gratefully acknowledge support from the Danish and Swedish Research Councils (SNF, TFR, STINT). This work was partially supported by the Office of Naval Research (G.D.S., J.D.B., S.L., A.E.C.P.), and it made use of MRL Central Facilities supported by the National Science Foundation under Award No. DMR96-32716. Dr. R. L. Paul of NIST is thanked for the Cold Neutron Prompt Gamma Ray Activation Analysis.

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Abstract

That guest atoms donate electrons to framework atoms is a generally accepted concept. Nevertheless, evidence for the presence of neutral guest atoms in thermoelectric clathrate structures is presented in the form of experimental X-ray charge density analysis and X-ray absorption near-edge structure (XANES) data. The picture shows the deformation density (DD) determined by the maximum entropy method for Ba₈Ga₁₆Ge₃₀; the DD shows that both the Ba guest atoms are disordered.

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Volume39, Issue20

October 16, 2000

Pages 3613-3616

Experimental Charge Densities of Semiconducting Cage Structures Containing Alkaline Earth Guest Atoms

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Experimental Charge Densities of Semiconducting Cage Structures Containing Alkaline Earth Guest Atoms

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