Effects of different amount of As2O3 and TiO2 on the chemical, physical and electrical properties of the base material MnO2

MnO2 oxide systems containing different weight percent of TiO2 and As2O3 were prepared. A number of studies, i.e., FTIR, X-ray powder diffraction, electrical conductivity and dielectric properties were carried out on these mixed oxide systems. It was shown that the doping amount of As2O3 and TiO2 influences structure, conductance, electrical and dielectric behaviour of the MnO2 system. Optical investigations showed that MnO2 reacts with As2O3 to form Mn2As2O7 and Mn2O3. TiO2 appears in the form of rutile phase. Dielectric constants epsilon' and epsilon" of 5 wt% As2O3-doped composite were calculated to be about 30 and about 38 at 13.5 kHz, respectively. The formation of Mn2As2O7, Mn2O3 and the presence of TiO2 rutile phase and the degree of polarisation or charge displacement depending on frequency played an effective role in the magnitude of epsilon', epsilon" and sigma. 23 refs.