| Autor: |
Mesbah A; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208-3113 , United States.; ICSM, UMR 5257 CEA, CNRS, ENSCM , Univ. Montpellier , Site de Marcoule-Bât. 426 , BP 17171, 30207 Bagnols-sur-Cèze , France., Prakash J; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208-3113 , United States.; Department of Chemistry , Indian Institute of Technology Hyderabad , Kandi, Sangareddy , Telangana 502285 , India., Beard JC; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208-3113 , United States., Malliakas CD; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208-3113 , United States., Ibers JA; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208-3113 , United States. |
| Abstrakt: |
Single crystals of K(Th 0.75 Sr 0.25 ) 2 Se 6 were obtained by a standard solid-state chemistry route at 1173 K. This compound does not belong to the AAn 2 Q 6 family (A = K, Rb, Cs, or Tl; An = Th, U, or Np; Q = S, Se, or Te) that possesses infinite Q-Q-Q chains and where a charge distribution of A + , 2 × An 4+ , 2 × Q 2- , 2 × (Q 2 2.5- ) has been proposed and hence a charge of -1.25 on Q of the "dichalcogenide". Rather in K(Th 0.75 Sr 0.25 ) 2 Se 6 , where the Th and Sr cations randomly occupy the same site, incorporation of these differently charged cations breaks the infinite Se-Se-Se chains into a structure that has typical Se 2 2- pairs. |
