Dielectric Properties of Sr2 +xBi4 −xTi5 −xTaxO18 Ferroceramics

Resumo

Samples of a new layered Sr_{2 +x}Bi_{4 −x}Ti_{5 −x}Ta_xO₁₈ (х = 0–0.8) perovskite are produced using state-of-the-art ceramic technology. Their dielectric properties are studied at frequencies of 25 Hz–1 MHz in a wide range of temperatures. It is established that a region undergoing a ferroelectric phase transition acquires 1/f ^α-type polarization noise. Analysis of parameter α as a function of temperature reveals a feature at a temperature near the Curie temperature, the value of which depends on the concentration of Ta.