Tuning of dielectric, pyroelectric and ferroelectric properties of 0.715Bi0.5Na0.5TiO3-0.065BaTiO3-0.22SrTiO3 ceramic by internal clamping

Abstract

Influence of structural evolution on energy storage properties in Bi 0.5 Na 0.5 TiO 3 -SrTiO 3 -NaNbO 3 lead-free ferroelectric ceramics Journal of Applied Physics 121, 054103 (2017) This study systematically investigates the phenomenon of internal clamping in ferroelectric materials through the formation of glass-ceramic composites. Leadfree 0.715Bi 0.5 Na 0.5 TiO 3 −0.065BaTiO 3 −0.22SrTiO 3 (BNT-BT-ST) bulk ferroelectric ceramic was selected for the course of investigation. 3BaO − 3TiO 2 − B 2 O 3 (BTBO) glass was then incorporated systematically to create sintered samples containing 0%, 2%, 4% and 6% glass (by weight). Upon glass induction features like remnant polarization, saturation polarization, hysteresis losses and coercive field could be varied as a function of glass content. Such effects were observed to benefit derived applications like enhanced energy storage density ∼174 k J/m 3 to ∼203 k J/m 3 and pyroelectric coefficient 5.7x10 −4 Cm −2 K −1 to 6.8x10 −4 Cm −2 K −1 by incorporation of 4% glass. Additionally, BNT-BT-ST depolarization temperature decreased from 457K to 431K by addition of 4% glass content. Glass incorporation could systematically increases diffuse phase transition and relaxor behavior temperature range from 70 K to 81K and 20K to 34 K, respectively when 6% and 4% glass content is added which indicates addition of glass provides better temperature stability. The most promising feature was observed to be that of dielectric response tuning. It can be also used to control (to an extent) the dielectric behavior of the host ceramic. Dielectric permittivity and losses decreased from 1278 to 705 and 0.109 to 0.107 for 6% glass, at room temperature. However this reduction in dielectric constant and loss increases pyroelectric figures of merit (FOMs) for high voltage responsivity (F v ) high detectivity (F d ) and energy harvesting (F e ) from 0.018 to 0.037 m 2 C −1 , 5.89 to 8.85 µPa −1/2 and 28.71 to 61.55 Jm −3 K −2 , respectively for 4% added ceramic-glass at room temperature. Such findings can have huge implications in the field of tailoring ferroelectric response for application specific requirements. C 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License. [http://dx

The effects of Ba2+ content on depolarization temperature and pyroelectric properties of lead-free 0.94Na0.5Bi0.5TiO3–0.06Ba1+xTiO3 ceramics

“…Table 2 also lists the p value (4.14 9 10 -4 C m -2°C-1 ) of a typical PZT ceramic measured at RT as a reference. The prepared NBT-0.06B 1?x T at x = 0.01-0.03 in this research show the comparable pyroelectric coefficients (3.30-3.5 9 10 -4 C m -2°C-1 ) [5,6,9].…”

“…There are several numbers of FOMs which are more appropriate to certain pyroelectric materials applications [6,27] and are derived from these application requirements. Pyroelectric coefficient (p) and the FOMs were analysed by using the following equations: [5,15,28] Ip ¼ pA dT dt ð1Þ…”

“…Pyroelectric ceramic materials are becoming increasingly on high demand in variety of industrial applications such as sensors, infrared detectors, thermal cameras, gas detectors, microelectronic devices, as well as actuators, transducers, medical devices, airplanes and spacecraft [6]. These materials could have a large pyroelectric coefficient (polarization change vs temperature change) at a phase transition temperature.…”

Large pyroelectric properties at reduced depolarization temperature in A-site nonstoichiometry composition of lead-free 0.94Na x Bi y TiO3–0.06Ba z TiO3 ceramics

“…This may be linked to the microstructural change due to the change of the stoichiometric state of this composition. Composition B has a bigger c/a ratio than all other compositions ( Table 1), indicating that Composition B has more tetragonality in its structure than all other compositions [13,43,44,46,47]. Importantly, at RT, the p values for nonstoichiometry compositions are higher than that of PZT and other lead-free compositions (Table 2) [7,19,27,32].…”

Pyroelectric performance of porous Ba0.85Sr0.15TiO3 ceramics

“…This complex relationship between thermal (specific heat) and dielectric properties (dielectric constant and dielectric loss) helps in tuning the pyroelectric performance for device applications. The physical or chemical compositional modifications technique is one such method which has been adopted in the past to chemically tune their pyroelectric performance . The composites seem to be another solution to tune all physical properties as per requirements.…”