Correlation between Phase Evolution, Physical and Electrical Properties of (Bi_0.5(Na_0.80K_0.20)_0.5)_1-x(Ba_0.7Sr_0.3)_xTiO₃ Lead-Free Piezoelectric Ceramics

Abstract

The (Bi_0.5(Na_0.80K_0.20)_0.5)_1-x(Ba_0.7Sr_0.3)_xTiO₃ or (BiNK)_1-x(BaS)_xT (x = 0, 0.01, 0.02, 0.03, 0.04, 0.05 and 0.06 mol fraction) lead-free piezoelectric ceramics were firstly made by a conventional one step mixed-oxide method and sintered at 1125 °C for 2 h with a heating rate of 5 °C/min. All samples showed optimum relative densities of ∼97–98%. The XRD result indicated that no impurity phase was detected in all fabricated samples. SEM images indicated that all ceramics possessed irregular shaped grains. It was also found that BST added content had an effect on electrical properties of BNKT ceramics. The highest piezoelectric coefficient (d₃₃ = 164 pC/N) with good dielectric (ε_r = 1577, tanδ = 0.0855) and ferroelectric properties (P_r = 11.38 µC/cm², E_c = 19.89 kV/cm) were obtained for (BiNK)_0.98(BaS)_0.02T sample.

Keywords:

• Lead free piezoelectric ceramics
• bismuth sodium potassium titanate
• dielectric behavior

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research project is supported by TSRI and National Research Council of Thailand (NRCT):NRCT5-RSA63004-15. Partial supports from the Center of Excellence in Materials Science and Technology, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University are also acknowledged. P. Wannasut and P. Jaita would like to acknowledge funding from the Office of Research Administration, Chiang Mai University. M. Promsawat would like to thank Rubber Product and Innovation Development Research Unit (SCIRU63002).