Effect of Rb substitution on dielectric, ferroelectric, mechanical and biocompatibility properties of Na0.2K0.3Bi0.5TiO3 ceramics

This study focuses on the strategically developed Rb-substituted lead-free Na0.2K0.3Bi0.5TiO3 (NKBT) ceramic, highlighting its applications in energy storage, bio-implants, actuators, dielectric capacitors, and various other fields. The significant decrement of average grain size of ∼0.31 μm from ∼0.62 μm has been observed via surface morphology analysis with ultra-high Vickers hardness of ∼8 GPa in Na0.2K0.24Rb0.06Bi0.5TiO3 (RB 6) which is within the range to use bio-implants. The biocompatibility of samples verified cell growth and was monitored using two fluorescence dyes: fluorescein diacetate (FDA for live cell staining) and propidium iodide (PI for dead cell staining) under a fluorescence microscope. Also, the findings reveal that Rb-NKBT exhibits excellent biocompatibility with normal fibroblast cells and possesses impressive mechanical strength. Moreover, The X-ray and Raman inquiry confirms the tetragonal crystal structure of the samples. Frequency-dependent dielectric curve and shifting of Tm reveal the enhanced relaxor property with broadening signifies the increase in thermal stability. It is an important parameter for biological applications, particularly those involving functional temperatures, as the material must remain ferroelectric within the operating temperature range. Furthermore, the higher breakdown strength of ∼110 kV/cm with a recoverable energy storage density of 0.62 J/cm3 was found in the RB 6. The S-ve of the material decreases with the substitution of the Rb, which has been useful for actuator application. This study offers a comprehensive discussion on the utility of NKBT FCs as an active functional material for biomedical applications and dielectric applications with the advantage of non-invasive evaluation for potential failure with their sensing applications. [Display omitted] •Lead-free ferroelectric ceramic prepared by cation engineering method.•The ultra-high Vickers hardness of the material ∼8 GPa was found in RB 6.•The recoverable energy storage density of 0.62 J/cm3 was found in RB 6.•The biocompatibility of samples verified using two fluorescence dyes.•Dielectric analysis confirms the enhanced relaxor property.