Röntgenographische und spektroskopische Untersuchungen an Silber(I)-halogenid-Thiometallaten und Argyroditen : Struktur-Eigenschafts-Beziehungen fester Elektrolyte

This thesis will give an overview over new adduct compounds of silver(I) halide thiometalates ((AgI) 2 Ag 3 MS 3 , M = As, Sb and (AgBr) 1.25 (Ag 2 S) 0.25 Ag 3 SbS 3 ) as well as quaternary copper argyrodites (Cu 8-x MQ 6-x X and Cu 7-x M’Q 6-x X; M = As, Sb; M’ = Si, Ge; Q = S, Se; X = Cl, Br
,I; 0
The work on the silver(I) halide thiometalates is focused on the determination of the crystal structures, the prove of the adduct character and the electrical properties, particularly the ionic conductivity.
Based on the results of single crystal structure determinations within the temperature range of 173 K – 573 K and a detailed analysis of the conductivities (impedance measurements) structural aspects, e. g. binding forces of the mobile ions to the anionic framework, distances between atomic positions (not fully occupied) and type and composition of the anionic framework with respect to the conductivity are discussed.
Silver(I) halide thiometalates are without exception mixed electric conductors. The ionic part of conductivity is dominating the electronic part. A preferred two dimensional transport of silver ions parallel to outstanding structure units could be observed.
Raman and infrared spectroscopic examinations are proving the adduct character of the silver(I) halide thiometalates. Spectra are dominated by streching modes of thiometalate units.
The second part of the thesis, dealing with examinations on quaternary copper argyrodites, is focused on the structure determination and phase analysis of insufficiently characterised compounds. The argyrodites are characterised by a rigid anionic framework which can be easily described by plane shared, centred Friauf polyhedra. An expressive model to describe the complex cationic part of the crystal structures will be discussed.
jpdf (joint probability density function) analysis leads to the conduction paths of copper. Effective one particle potentials are derived from the jpdf along the conduction paths. With respect to the low activation energies (
Thermoanalytic- and NMR-spectroscopic measurements are proving the occurrence of phase
transitions in the examined systems.