Cu Insertion Into the Mo12 Cluster Compound Cs2Mo12Se14: Synthesis, Crystal and Electronic Structures, and Physical Properties.
Mo-based cluster compounds are promising materials for high-temperature thermoelectric applications due to their intrinsic, extremely low thermal conductivity values. In this study, polycrystalline cluster compounds Cs2CuxMo12Se14 were prepared for a wide range of Cu contents (0 ≤ x ≤ 2). All samples crystallize isostructurally in the trigonal space group R3̅. The position of the Cu atoms in the unit cell was determined by X-ray diffraction on a single-crystalline specimen indicating that these atoms fill the empty space between the Mo-Se clusters. Density functional theory calculations predict a metallic ground state for all compositions, in good agreement with the experimental findings. Magnetization measurements indicate a rapid suppression of the superconducting state that develops in the x = 0.0 sample upon Cu insertion. Transport properties measurements, performed in a wide temperature range (2-630 K) on the two end-member compounds x = 0 and x = 2, revealed a multiband electrical conduction as shown by sign reversal of the thermopower as a function of temperature.
Institut des Sciences Chimiques de Rennes , UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex, France.
Rabih
R
Al Rahal Al Orabi
Institut des Sciences Chimiques de Rennes , UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex, France.
Bruno
B
Fontaine
Institut des Sciences Chimiques de Rennes , UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex, France.
Regis
R
Gautier
Institut des Sciences Chimiques de Rennes , UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex, France.
Patrick
P
Gougeon
Institut des Sciences Chimiques de Rennes , UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex, France.
Philippe
P
Gall
Institut Jean Lamour , UMR 7198 CNRS-Université de Lorraine, Parc de Saurupt, CS 50840, 54011 Nancy, France.
Yohan
Y
Bouyrie
Institut Jean Lamour , UMR 7198 CNRS-Université de Lorraine, Parc de Saurupt, CS 50840, 54011 Nancy, France.
Anne
A
Dauscher
Institut Jean Lamour , UMR 7198 CNRS-Université de Lorraine, Parc de Saurupt, CS 50840, 54011 Nancy, France.
Christophe
C
Candolfi
Institut Jean Lamour , UMR 7198 CNRS-Université de Lorraine, Parc de Saurupt, CS 50840, 54011 Nancy, France.
Bertrand
B
Lenoir