Structural transformation in Mn-substituted Sr2Bi2Ta2TiO12 Aurivillius phase synthesized by hydrothermal method: A comparative study and dielectric properties

Abstract In this study, a hydrothermal method was applied to synthesize the three-layer Aurivillius phase Sr2Bi2Ta2TiO12 (SBTTO) and Mn-substituted Sr1·5Bi2·5Ta2Ti0·5Mn0·5O12 (SBTTMO), with use of NaOH as mineralizer. The crystal structure, morphology, dielectric properties, correlation between structural transformation properties were investigated. XRD data reveal that SBTTO sample adopts tetragonal structure I4/mmm space group is then transformed into an orthorhombic B2cb for SBTTMO. morphology both samples observed by SEM, which showed anisotropic plate-like grains. With Mn substitution, ferroelectric transition temperature (Tc) significantly increases influence 6s2 lone pair Bi3+ increases, in turn further induces relaxor-ferroelectric behavior. Consequently, increase Tc confirms from paraelectric-tetragonal ferroelectric-orthorhombic phase.