Impedance spectroscopic studies in SrBi4Ti4O15

The impedance measurements have been performed in the temperature range of 30 to 600 degreesC and the frequency range 1 kHz to 10 MHz on four-layered SrBi4Ti4O15. The imaginary components of impedance Z ", the electrical modu lus M " and ac conductivity have been computed, both as a function of frequ ency and temperature. The peaks appear in Z " versus frequency plots and th ey shift towards lower frequencies at the temperature up to 500 degreesC an d above 525 degreesC they shift towards higher frequencies. Similar behavio ur is observed, in M " versus frequency plots. \Z " \ values decrease with increase of temperature, while \M " \ values decrease up to 500 degreesC an d above 525 degreesC these values are found to increase with. temperature. Complex impedance diagrams are nearly semicircles at higher temperatures. R esults are interpreted. in terms of possible conductivity mechanisms presen t in the sample.