Impact of Sm-substitution and microwave sintering on dielectric and mechanical properties of SrBi < inf > 4 < /inf > Ti < inf > 4 < /inf > O < inf > 15 < /inf > ceramics

Abstract

In quest of finding an alternative for lead-based materials, ferroelectric materials with Bi-layered structure have attracted great attention due to their potential applications in non-volatile memory, electro-optic devices, and microelectromechanical systems. In this work, samarium (Sm)-substituted SrBi4Ti4O15 (SBTi) ceramics have been prepared by solid-state reaction method and sintered using microwave, as well as conventional heating. XRD phase analysis reveals the formation of single phase compound, and there is no effect of Sm-substitution on basic crystal structure. SEM micrographs showed the plate-like structure of grains both in microwave and conventional furnace. Temperature-dependent dielectric properties were investigated in the temperature range 40–600 °C and frequency range 10 kHz–1 MHz. Sm-substitution increases dielectric constant upto Sm ~ 0.75 and also introduces small relaxor behavior. Hardness and Young’s modulus of SrBi4-xSmxTi4O15 ceramics were measured by nanoindentation. The structural, morphology, dielectric, and mechanical properties of pure and substituted SrBi4Ti4O15 ceramics along with sintering methods have been investigated in detail.