Synthesis and properties of type-I clathrate phases Rb(8-x-t)K(x□t)Au(y)Ge(46-y).
Type-I clathrates Rb(8-x-t)K(x□t)Au(y)Ge(46-y) are synthesized from Rb4Ge9, K4Ge9, Au, and Ge. Crystal structures and compositions are determined by single-crystal and powder X-ray diffraction methods. The lattice parameters are 10.8103(2), 10.7956(2), 10.7850(2), and 10.7723(2) Å in space group Pm3n for Rb7.88(2)Au2.47(2)Ge43.53(2), Rb3.69(4)K4.31(4)Au2.17(2)Ge43.83(2), Rb1.66(5)K6.34(5)Au2.17(1)Ge43.83(1), and K6.71(4)Au2.28(2)Ge43.72(2), respectively. Bonding analysis for Rb8Au6Ge40 suggests ionic interaction of Rb with the framework besides covalent interactions between Ge and Au/Ge. Rb7.88Au2.47Ge43.53 and K6.71(4)Au2.28Ge43.72 are both diamagnetic. The heat capacity of K6.71Au2.28Ge43.72 is analyzed. Transport properties of Rb7.88Au2.47Ge43.53 reveal n-type conducting, and low thermal conductivity.
Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany. huizhangmpg@hotmail.com
H
H
Zhang
M
M
Baitinger
L
L
Fang
W
W
Schnelle
H
H
Borrmann
U
U
Burkhardt
A
A
Ormeci
J T
JT
Zhao
Yu
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Grin