Structural disorder and relaxation processes in Li-containing solid solutions with the structure of the tetragonal potassium-tungsten bronze

Temperature and frequency dependences of permittivity have been determined for two series of oxides, with the structure of the tetragonal potassium-tu ngsten bronze containing vacancies and Li ions in the unit cells. Dielectri c dispersions were established for the K2 - yPb4LiyNb10O30 oxide series in the infra-low frequency range (10(-2)-10(2) Hz) and for the BaxPb4 - xLi2Nb 10O30 series in the 10(-2)-10(7) Hz frequency range. The existence of diele ctric dispersions is explained by the specific distributions of Pb and Li i ons in the crystal structures of the tetragonal potassium-tungsten bronze.