| Autor: |
Mesbah A; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston 60208-3113 , Illinois , United States.; ICSM, UMR 5257 CEA, CNRS, ENSCM, Université de Montpellier , Site de Marcoule-Bât. 426 , BP 17171, Bagnols-sur-Cèze 30207 , France., Prakash J; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston 60208-3113 , Illinois , United States.; Department of Chemistry , Indian Institute of Technology Hyderabad , Kandi, Sangareddy 502 285 , Telangana , India., Lebègue S; Laboratoire de Physique et Chimie Théoriques (LPCT, UMR CNRS 7019), Institut Jean Barriol, Université de Lorraine , BP 239, Boulevard des Aiguillettes , Vandoeuvre-lès-Nancy 54506 , France., Beard JC; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston 60208-3113 , Illinois , United States., Malliakas CD; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston 60208-3113 , Illinois , United States., Ibers JA; Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston 60208-3113 , Illinois , United States. |
| Abstrakt: |
The structure of Ag 5 U(PS 4 ) 3 is unique, as in the literature there are no other structures of the type MAnPQ (M = transition metal, An = actinide, Q = S, Se, or Te). The compound has been synthesized at 1123 K by standard solid-state methods, and its single-crystal X-ray structure has been determined at 100(2) K. Ag 5 U(PS 4 ) 3 crystallizes in a remarkable new structure type in space group P3 2 21 of the trigonal system with three formula units in a hexagonal cell of dimensions a = b = 9.6635(2) Å, c = 17.1834(4) Å, and γ = 120°. In the structure, each U atom is coordinated to eight S atoms in a bicapped trigonal prismatic manner. Each P atom is tetrahedrally coordinated to four S atoms. Two of the three unique Ag atoms are connected to four S atoms in a distorted tetrahedral manner, whereas the third unique Ag atom forms an Ag 2 S 6 species. The overall structure consists of U polyhedra connected to each other via PS 4 tetrahedra through edge-sharing in a zigzag fashion along the c axis to form infinite layers. PS 4 groups and the Ag atoms pack these layers. From density functional theory calculations, the total density of states of Ag 5 U(PS 4 ) 3 is asymmetric with respect to spin and has finite spin polarization in the crystal cell: the magnetic moments of two of the U atoms are parallel, whereas the magnetic moment of the third U atom is antiparallel. |
