Ferroelectric and dielectric study of Y3+ substitution at Bi-site on SrBi2Ta2O9 ferroelectric ceramic

Aurivillius SrBi2-xYxTa2O9 ceramics have been prepared by modified solid state route. Structural and electrical properties of modified SrBi2Ta2O9 ceramic are studied as a function of Yttrium content. The X-ray diffraction patterns indicated that the perovskite phase is fully formed with polycrystalline structure in all the compositions. The morphological study is done by Scanning electron microscopy, which shows plate like anisotropic structure. Raman spectra identified that all the major modes are available of the layered structure and a little amount of broadness in the spectra is indicated that the stress formed in the modified ceramics. The temperature dependent dielectric study shows a diffuse phase transition with a linear decrease in transition temperature and dielectric constant with an increase in Y content. The ferroelectric property is studied by P–E hysteresis loop and the loop is fitted using ferroelectric capacitor modeled equation which gives good agreement with the experimental data.