Heating rate effect on dielectric, ferroelectric and piezoelectric properties of Bi0.45La0.05Na0.40K0.10Ti0.98Zr0.02O3 Pb-free piezoelectric ceramic for actuator applications

• Published in: Ferroelectrics 2019-11, Vol.552 (1), p.32-41
• Main Authors: Butnoi, Pichitchai, Manotham, Supalak, Rujijanagul, Gobwute
• Format: Article
• Language: English
• Subjects: Actuators; Ceramics; Cooling; Cooling rate; Densification; Dielectric properties; Electrical properties; Electrostriction; Ferroelectric materials; Ferroelectricity; Heating rate; Hysteresis loops; Lead free; lead-free BLNKZT ceramics; Perovskite structure; Perovskites; Photomicrographs; Piezoelectric ceramics; Piezoelectricity; Sintering
• ISSN: 0015-0193; 1563-5112
• DOI: 10.1080/00150193.2019.1653080

In this present work, the effect of heating/coolling rate on the electrical properties such as ferroelectric, dielectric and electrostrictive properties of Pb-free Bi 0.45 La 0.05 Na 0.40 K 0.10 -Ti 0.98 Zr 0.02 O 3 or BLNKZT piezoelectric ceramics has been systematically investigated. The BLNKZT ceramics were prepared via a conventional solid state reaction method and sintered at 1125 °C for 2 h, which applied the heating/cooling rates of 5, 10 and 15 °C/min in order to clarify the optimal parameter for densification and good electrical properties. The XRD pattern exhibited a complete single perovskite structure with a pseudo-cubic phase at the rate of 5 °C/min sample and tranformed to tetragonal-rich phase at the rate of 15 °C/min. The SEM micrograph of all BLNKZT ceramics showed a cubic-like grain shape. The P-E hysteresis loop was measured at the temperatures ranging from −40 to 120 °C. With increasing temperature, the P r and E c values distinctly decreased and the P-E loops tended to deform and showed pinch loops. The maximum strain (S max ) value of 0.10% and calculated normalized strain (d* 33 ) of 167 pm/V (measured at 60 kV/cm) were obtained for ceramic sintered with the heating/cooling rates of 5 °C/min.