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Piezoelectric Performance of Lead-Free BNGN Ceramics at MPB as a Green Material for Transduction Applications
Published in P. C. Thomas, Vishal John Mathai, Geevarghese Titus, Emerging Technologies for Sustainability, 2020
This makes them less susceptible to remnant polarization resulting in comparatively low values for dielectric and piezoelectric properties. Consequently, their potential for use as substitute for PZT based ceramics for practical applications is rather limited. This concern has led to intense experimental work on the induction of MPB in lead free ceramics by preparing solid compositions of two or more distinct lead-free ceramics. As a result, MPBs have been induced in Potassium Sodium Bismuth Titanate (KNBT), Barium Titanate–Sodium Bismuth Titanate (BT-NBT), Lithium Niobate etc., though there are still experimental concerns on their stability [4].
High-density lead-free K0.5Bi0.5TiO3 ceramics: preparation, mechanical and dielectric properties
Published in Phase Transitions, 2018
P. Czaja, J. Suchanicz, D. Bochenek, G. Dercz, M. Piasecki, W. Hudy
One of the most prospective lead-free material for replacing lead-based compounds is the potassium-bismuth titanate K0.5Bi0.5TiO3 (hereinafter referred to as KBT). This material, like sodium-bismuth titanate Na0.5Bi0.5TiO3 (hereinafter referred to as NBT), belongs to the group of compounds with a perovskite structure of general formula A0.51+Bi0.53+B4+O3. NBT is the ferroelectric at room temperature. It undergoes two structural phase transitions from rhombohedral to tetragonal structure over the range 533–623 K (a ferroelectric phase) and then to high-temperature paraelectric phase from tetragonal to cubic structure over the range 793–813 K [3–9]. Among the many advantages of NBT (e.g. an easy of preparing polycrystalline material, a low loss of piezoelectric properties at about 473 K, a high residual polarization in the polycrystalline materials of Pr = 25 μV/cm2), there are also disadvantages that limit the use of this material, e.g. for energy storage [8,10,11]. These include higher dielectric loss, larger conductivity and higher coercive field (∼73 kV/cm) [12]. On the other hand, KBT material can be more advantageous due to dielectric properties, but compared to NBT, this material is rarely studied. One of the reasons that may already arise at the technological level is the low density of sintered ceramics so far [13], which may make it difficult or even impossible to carry out required tests of this material [13]. The high volatility of bismuth and/or potassium which occurs at high temperature is one of the main reasons of formation of a secondary phase during the synthesis of KBT [14–16].
Effect of Nb-doping and E-poling on dielectric and electric properties of NBT ceramics
Published in Phase Transitions, 2021
J. Suchanicz, M. Wąs, M. Nowakowska-Malczyk, K. Konieczny, P. Czaja, K. Kluczewska-Chmielarz, J. Marchewka, D. Wcisło, R. Wolański, K. Stanuch, M. P. Trubitsyn, M. Sokolowski
Sodium bismuth titanate (Na0.5Bi0.5TiO3) (NBT) is the most promising candidate to replace Pb-based systems. However, relatively high electric conductivity and coercive field of NBT lead to problems with their E-poling for piezoelectric, ferroelectric and energy storage application [1]. Doping of NBT by different ions can lead to improve their electric field poling conditions.
Isothermal depolarization currents of Na0.5Bi0.5TiO3 ceramics
Published in Phase Transitions, 2018
K. Kluczewska, D. Sitko, J. Suchanicz, P. Czaja, M. Sokolowski
Due to their promising properties, lead-free sodium-bismuth titanate Na0.5Bi0.5TiO3 (NBT)and NBT-based compounds have been intensively studied as a replacement of Pb-containing materials [1–5].