Über die Natur von Silbersubfluorid

Neutron powder diffraction study of silver subfluoride

“…To account for the difference in measured and calculated densities reported by Terrey and Diamond [9] the compound would require an average stoichiometry of Ag2FOg0 or Ag,,,,F for strictly F or Ag vacancies respectively. Even if all the vacancies were Ag our results are not adequate to explain the low measured densities of Ag2F by other experimenters [2]. Since the accuracy of both lattice parameter and density measurements is ordinarily quite high, this discrepancy remains a mystery unless a high density of some other form of defect exists in the material or the density of the material is strongly dependent on the method of preparation.…”

“…Hettich [2] also reports a rather low value for the measured density, in his case 8.57 g cmP3. In view of this we considered the possibility of the presence of defects in Ag,F in the form of both F vacancies and Ag vacancies.…”

“…The density of Ag,F has been measured by Terry and Diamond [9], who found that their experimentally obtained value, 8.64 g ~m -~, was somewhat lower than that obtained from a calculation using the lattice parameters which they determined from xray powder diffraction, 8.78 g ~m -~. Hettich [2] also reports a rather low value for the measured density, in his case 8.57 g cmP3. In view of this we considered the possibility of the presence of defects in Ag,F in the form of both F vacancies and Ag vacancies.…”

“…It can be prepared chemically [ 11 or electrolytically [2], but decomposes into Ag metal and AgF in the presence of moisture, ultraviolet light, or above 130 "C. The transport properties are very anisotropic, having a room-temperature resistivity parallel to the layers about two orders of magnitude less than that perpendicular to the layers [3]. While conduction parallel to the layers is clearly metallic, both semiconducting [3] and metallic [4] behaviour has been claimed for conduction along the c axis.…”