Mercouri G. Kanatzidis

CCDC 1576250: Experimental Crystal Structure Determination

Related Article: Daniel E. Bugaris, Christos D. Malliakas, Sergey L. Bud’ko, Nicholas P. Calta, Duck Young Chung, Mercouri G. Kanatzidis|2017|Inorg.Chem.|||doi:10.1021/acs.inorgchem.7b02389

Extraordinary Selectivity of CoMo[subscript 3]S[subscript 13] Chalcogel for C[subscript 2]H[subscript 6] and CO[subscript 2] Adsorption

or metals, [ 5 ] has recently been expanded to include the emerging new chalcogenide materials called chalcogels. [ 6–10 ] Unlike the nanocrystalline chalcogenide aerogels reported by Brock et al., [ 6 , 11 , 12 ] the chalcogels feature random amorphous networks similar to those of silica. Because of the “soft” nature of electron-rich chalcogen atoms, the polarizability of the internal surface of chalcogels is much higher than those of metal oxides, porous carbons, and organic polymers and therefore provides an entirely new medium through which to study the diffusion and separation of gases. [ 13 ] Photocatalysis, catalysis, gas separation, and removal of heavy metals with chalcogels are just some of the proposed applications that make use of the unique electronic properties (tunable bandgaps and high surface polarizability) of such high surface area materials. [ 8 ]

Transport properties of the doped thermoelectric material /spl beta/-K/sub 2/Bi/sub 8/Se/sub 13/

The synthesis, physicochemical, spectroscopic, and structural characterization of the compounds /spl beta/-K/sub 2/Bi/sub 8/Se/sub 13/, K/sub 2/Sb/sub 8/Se/sub 13/, K/sub 2.5/Bi/sub 8.5/Se/sub 14/, and K/sub 2.5/Sb/sub 8.5/Se/sub 14/ have been previously reported and show promising properties for thermoelectric applications. While /spl beta/-K/sub 2/Bi/sub 8/Se/sub 13/ is isostructural with K/sub 2/Bi/sub 7/S/sub 13/, the isostructural K/sub 2.5/Bi/sub 8.5/Se/sub 13/ and K/sub 2.5/Sb/sub 8.5/Se/sub 14/ are different but have similar structural features to /spl beta/-K/sub 2/Bi/sub 8/Se/sub 13/. Compared with /spl alpha/-K/sub 2/Bi/sub 3/Se/sub 13/, which has a room temperature electrical conductivity of 2 S/cm and a Seebeck coefficient ranging from -210 to -260 /spl mu/V/K, /spl beta/-K/sub 2/Bi/sub 8/Se/sub 13/ shows excellent electrical conductivity values at room temperature while maintaining high Seebeck coefficients. In this work the doping of the homologous compound /spl beta/-K/sub 2/Bi/sub 8/Se/sub 13/ was explored by employing varying concentrations of different dopants. Where possible, transport measurements were carried out on both single crystal and polycrystalline ingot material. From these data the trends in the key parameters were identified for optimizing the power factor and figure of merit.