Evaluation of the structure and electrical properties of (1−x)Bi0.5(Na0.80K0.20)0.5TiO3–xLiNbO3 ceramic composite for piezoelectric sensor applications

Abstract

Lead-free piezoceramics ([Formula: see text])Bi[Formula: see text](Na[Formula: see text]K[Formula: see text]TiO3–xLiNbO3 (BNKT–LN) (where [Formula: see text], 0.025, 0.050 and 0.075[Formula: see text]mol fraction) were examined for their ferroelectric stability and subsequent modifications. Traditional solid-state reaction techniques were used to create the BNKT–LN piezoceramics, which were then sintered at a temperature of 1200°C. We concentrated on the structural, dielectric, piezoelectric and ferroelectric properties of the BNKT–LN ceramics. The powder X-ray diffraction pattern revealed a single perovskite structure with no secondary phases, as was observed. The temperature-dependent dielectric curves demonstrated that the maximum dielectric constant ([Formula: see text]) is present in the pure BNKT sample and diffuses to a low value when the LN concentration rises. SEM confirms the material’s surface shape, and decreasing grain sizes are seen as the LN content rises. The BNKT–LN ceramics’ P–E hysteresis loops demonstrate good ferroelectric characteristics, with a maximum at 20 kV/cm. With an increase in LN concentration, remnant polarization ([Formula: see text]) and coercive field ([Formula: see text]) show a trend of increasing, reducing and then increasing. The maximum value of the piezoelectric coefficient ([Formula: see text]) for the combined samples was 147[Formula: see text]pC/N. As a result, the lead-free ceramic BNKT (BNKT–LN) doped with LN is an auspicious choice for piezoelectric sensor applications.