Nano/micro Sr2Bi4Ti5O18 crystallites: Size dependent structural, second harmonic and piezoelectric properties

• Nano/microcrystallites of Sr2Bi4Ti5O18 were synthesized via sol-gel route.
• Crystallite size dependent structural and physical properties were studied.
• SHG intensity (1.4 times that of KDP powder) from these crystallites was recorded.
• PFM studies on isolated crystallite of 480 nm exhibited d33 as high as 27 pm/V.
• Single domain nature of the crystallites below 160 nm was observed.

Strontium bismuth titanate (Sr2Bi4Ti5O18) powders comprising crystallites of average sizes in the range of 94–1400 nm were prepared via citrate-assisted sol-gel route. With an increase in the average crystallite size there was a change in the lattice parameters and shift in the Raman vibration modes. Second harmonic signal (532 nm) intensity of the Sr2Bi4Ti5O18 powders increased with the increase in the average crystallite size and the maximum intensity obtained in the reflection mode was 1.4 times as high as that of the powdered KH2PO4. Piezo Force Microscopic analyses carried out on isolated crystallite of size 74 nm, established a single domain nature with the coercive field as high as 347 kV/cm. There was a systematic increase in the d33 value with an increase in the size of the isolated crystallites and a high piezoelectric coefficient of ∼27 pm/V was obtained from an isolated crystallite of size 480 nm.

Synthesis of Sr2Bi4Ti5O18 nano/micro crystallites and their size dependent non-linear optical and piezoelectric responses.Figure optionsDownload as PowerPoint slide