M. Kanatzidis, J. Chou
Dec 1, 1996
Citations
0
Influential Citations
46
Citations
Journal
IEEE Journal of Solid-state Circuits
Abstract
Abstract Three new solid state silver selenoarsenates and one thioarsenate prepared from hydro- and methanothermal synthesis are described. β-Ag 3 AsSe 3 (I) and (Me 3 NH)[Ag 3 As 2 Se 5 ] (II) were synthesized hydrothermally at 110°C from a mixture of AgBF 4 /3K 3 AsSe 3 and AgBF 4 /3K 3 AsSe 3 /6Me 3 NHCl, while K 5 [Ag 2 As 3 Se 9 ] (III) and K[Ag 3 As 2 S 5 ] (IV) were synthesized methanothermally at 110°C from a mixture of AgBF 4 /3K 3 AsS 3 and AgBF 4 /3K 3 AsSe 3 , respectively. β-Ag 3 AsSe 3 (I) crystallizes in the orthorhombic space group Pnma (No. 62) with a = 8.111(1) A, b = 11.344(2) A, c = 20.728(3) A, Z = 8, V = 1907(1) A 3 . This compound is a new allotrope of α-Ag 3 AsSe 3 and has a complex three-dimensional structure composed of distorted trigonal planar and tetrahedral Ag + ions and [AsSe 3 ] 3− units. (Me 3 NH)[Ag 3 As 2 Se 5 ] (II) crystallizes in the triclinic space group P − 1 (No. 2) with a = 10.119(2) A, b = 18.010(4) A, c = 14.932(3) A, α = 110.20 (1)°, β = 103.98(2)°, γ = 99 99(1)°, Z = 2, V = 729.3(8) A 3 . The [Ag 3 As 2 Se 5 ] n − n anion in (II) has a complex two-dimensional layered structure with tetrahedral Ag + ions and [As 2 Se 5 ] 4− units. K 5 [Ag 2 As 3 Se 9 ] (III) crystallizes in the orthorhombic space group Pnma (No. 62) with a = 12.599(2) A, b = 12.607(4) A, c = 14.067(3) A, Z = 8, V = 2234(1) A 3 . The [Ag 2 As 3 Se 9 ] 5 n − n anion in (III) has a two-dimensional layered structure with tetrahedral Ag + ions and two different kinds of selenoarsenate units, [AsSe 4 ] 3− and [As 2 Se 5 ] 4− . K[Ag 3 As 2 S 5 ] (IV) also crystallizes in the orthorhombic space group Pnma (No. 62) with a = 19.210(2) A, b = 16.867(2) A, c = 6.3491(7) A, Z = 8, V = 2057.2(7) A 3 . The [Ag 3 As 2 S 5 ] n − n anion in (IV) possesses a complicated two-dimensional structure with tetrahedral Ag + ions and two kinds of thioarsenate ligands, [AsS 3 ] 3− and [As 3 S 7 ] 5− . The thermal stability and optical absorption properties of these compounds are reported.