Ternäre Halogenide vom Typ A3MX6. IV. [1]. Ternäre Halogenide des Scandiums mit Natrium,Na3ScX6 (X = F,Cl, Br): Synthese,Strukturen, Ionenleitfähigkeit |
| |
Authors: | Andreas Bohnsack Gerd Meyer |
| |
Abstract: | Ternary Halides of the A3MX6 Type. IV. Ternary Halides of Scandium with Sodium, Na3ScX6 (X = F, Cl, Br): Synthesis, Structures, Ionic Conductivity X-ray studies on single crystals of Na3ScF6 and Na3ScBr6 show, that Na3ScF6 crystallizes with the cryolite type (monoclinic, P21/n, Z = 2, a = 560.16(9), b = 580.31(8), c = 812.1(2)pm, β = 90.720(14)°) and Na3ScBr6, as the only ternary bromide of the rare earth elements with sodium, in the Na3CrCl6 type (trigonal, P3 1c, Z = 2, a = 728.95(7), c = 1309.29(17)pm). The ionic conductivity of powder samples of Na3ScF6, Na3ScBr6 and of Na3ScCl6 was studied by impedance spectroscopy. Activation energies were determined as 1.22 eV, 0.80 eV and 0.71 eV for the fluoride, chloride and bromide, respectively. The differences are explained from the crystal structures and the sizes and polarizabilities of the anions. |
| |
Keywords: | Scandium Halides Crystal Structures Ionic Conductivity |
|
|