Beschreibung:
AbstractTwo new silver solid electrolytes, Ag4I2SeO4 and Ag3ITeO4, have been synthesized by solid state reactions starting from stoichiometric mixtures of Ag2O and AgI with SeO2, or TeO2, respectively, at elevated oxygen pressures. The new materials have been characterized using powder X‐ray diffraction, differential scanning calorimetry, ionic conductivity measurements and single crystal structure determination. Both compounds, Ag4I2SeO4 and Ag3ITeO4, show an abrupt increase in the ionic conductivity in the temperature range of 50 to 70 °C and 90 to 130 °C, respectively. Ag4I2SeO4 has a silver ion conductivity of 1.6 × 10−3 at 30 °C with an activation energy of 0.22 eV, between 30 and 51 °C. It crystallizes as green crystals in Pna21 with a = 9.3514(1) Å, b = 13.1552(4) Å, c = 7.0886(4) Å, V = 871.80(6) Å3 and Z = 4. The crystal structure consists of isolated SeO4 tetrahedra separated by Ag+ and I− ions. Ag3ITeO4 crystallizes in P21/c with a = 19.6597(2) Å, b = 7.1240(4) Å, c = 13.3598(3) Å, β = 97.795(2)°, V = 1853.83(11) Å3 and Z = 12. The structure consists of $^{1}_{\infty}\rm [TeO_{4/2}O_{2/1}]^{2-}\}$ isopolyanions, extending along the b‐axis. The chains are separated by Ag+ and I− ions. Ag3ITeO4 has a silver ion conductivity of 7.4 × 10−5 Ω−1 cm−1 at 30 °C, with an activation energy of 0.27 eV between 25 and 100 °C.