BaTiO3 Template Research Articles

Textured Pb(Mg1/3Nb2/3)O3 −Pb(In1/2Nb1/2)O3 −PbTiO3 ceramics with enhanced piezoelectric properties and high Curie temperature prepared by low-temperature sintering

A low-temperature sintering is crucial for the fabrication of multilayer piezoceramic actuators through low-cost internal metal electrodes. Herein, Pb(Mg1/3Nb2/3)O3−Pb(In1/2Nb1/2)O3 −PbTiO3 (PMN−PIN−PT) textured ceramics were prepared by a combined use of refined matrix powder and CuO sintering additive. When the matrix powder was refined by planetary ball-milling for 10 h, the sintering temperature of the textured 0.37PMN−0.29PIN−0.34PT ceramics was lowered to 1175 ºC, and a subsequent addition of 1 mol% CuO further lowered it to 950 ºC. The textured 0.37PMN−0.29PIN−0.34PT ceramics with 3 vol% BaTiO3 (BT) template sintered at 950 ºC for 10 h yielded excellent piezoelectric properties, such as a Lotgering factor (LF) of 97%, a unipolar strain of 0.23% at 2 kV/mm, and a Curie temperature (TC) of 231 ºC. These enhanced piezoelectric properties and high TC result from the high texture, transient liquid phase sintering, Cu2+ ion doping, and minimum BT template content.

Preparation of Pb(Mg1/3Nb2/3)TiO3–PbTiO3 thick films with highly preferred orientation via screen printing

Rhombohedral 0.75Pb(Mg1/3Nb2/3)TiO3–0.25PbTiO3 (PMN-25PT) and tetragonal 0.65Pb(Mg1/3Nb2/3)TiO3–0.35PbTiO3 (PMN-35PT) thick films with a highly preferred orientation were prepared via screen printing on MgO and YSZ ceramic substrates. The use of oriented BaTiO3 thick films as template layers was effective in forming the oriented PMN-25PT and PMN-35PT thick films. The orientation degrees of both thick films were over 0.85. The formation process of the thick films was examined using electron backscatter diffraction. PMN-25PT grains grew on the BaTiO3 template layers and aligned with the BaTiO3 orientation direction. Finally, the PMN-25PT and PMN-35PT thick films prepared on MgO had better electrical properties than the thick films fabricated on YSZ.

Comprehensively enhanced strain performance in PIN-PMN-PT ferroelectric ceramics via composition and orientation engineering

Excellent overall strain performances (i.e., low hysteresis, giant strain, and wide temperature span) are highly desirable in commercial high-precision displacement actuators to satisfy different application scenarios. However, any single means, e.g., compositional design or orientation engineering can hardly achieve the overall improvement of strain properties in ceramics. In this work, an approach of integrating compositional design (Sm and Mn co-doping) and orientation engineering (<001>-textured) is proposed to enhance the strain performance of 0.27Pb(In1/2Nb1/2)O3-0.40Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (PIN-PMN-PT) comprehensively. Initially, with the co-doping of Sm and Mn, the hysteresis of PIN-PMN-PT is substantially decreased to approximately 0.43 times that of the undoped material. Subsequently, 5 wt% BaTiO3 (BT) templates were added during the tape-casting process to orient the grains in 1 mol% Sm and Mn-doped PIN-PMN-PT ceramics. This resulted in a unique "4R" domain configuration with a reduced domain size of 0.13 µm. As a result, the domain wall energy was lowered, and the strain strength was increased to 0.35% at 70 kV/cm with low hysteresis to 8.94%. Moreover, the "clamping effect" in textured ceramics generates additional stress due to the lattice mismatch between the matrix grains and the BaTiO3 template, which inhibits the rhombohedral to the tetragonal phase transition. In addition, the fluctuation of strain value was only 8.5% over a wide temperature range of 30–150 °C, demonstrating excellent temperature stability. As a result of the combined effect of ion doping and orientation engineering, the overall strain performance in PIN-PMN-PT has been improved, providing a novel approach to designing superior and practical displacement actuators.

High piezoelectric response in [001] textured Sm3+ doped Pb(Mg1/3Nb2/3)O3–PbTiO3 ceramics

In this work, [001] textured Sm0.025Pb0.9625(Mg1/3Nb2/3)0.74Ti0.26O3 (Sm-PMN-26PT) ceramics were synthesized by the templated grain growth method. The dielectric, piezoelectric, and electromechanical properties of untextured and textured ceramics are systematically studied. A high texture degree of 99% was obtained using 1% volume fraction of the BaTiO3 (BT) template. The textured ceramics exhibit an excellent piezoelectric coefficient d33 of 1882 pC/N at room temperature, and an extremely high d33* of 2510 pm/V is obtained. The dielectric, ferroelectric, and strain characteristics reveal that the improvement of piezoelectric properties of textured ceramics comes from the increase of dielectric constant ε33 and electrostriction coefficient Q33. Both the intrinsic response of the domain and the external contribution of the domain wall are enhanced in [001] textured ceramics, which may be the microscopic mechanism of increased piezoelectric activity. The Sm-PMN-26PT textured ceramics exhibit excellent piezoelectric properties, which are very promising for using at room temperature.

Determining the effects of BaTiO3 template alignment on template grain growth of Pb(Mg1/3Nb2/3)O3 –PbTiO3 and effects on piezoelectric properties

Crystallographic texturing of ferroelectric ceramics is an established method of inducing single crystal-like properties in a ceramic material via epitaxial grain growth according to the template used, otherwise known as Templated Grain Growth (TGG). The piezoelectric enhancement is dependent on the degree of TGG throughout the ceramic, which is closely linked to the tape casting parameters and sintering conditions. Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) perovskite ferroelectrics with morphotropic phase boundary compositions using 3 vol% BaTiO3 templates were used for analysis. The blade gap and template size have the greatest impact on the overall grain alignment. The varying degrees of template alignment is related to the different enhancements of TGG and the correlating piezoelectric d33 and d*33. The highest piezoelectric property was demonstrated in PMN-31PT with Lotgering factor of 93% where d33 = 1020 pC/N and d*33 = 1420 pm/V were achieved.

Outstanding unipolar strain of textured Pb(Mg1/3Nb2/3)O3–PbZrO3–PbTiO3 piezoelectric ceramics manufactured by particle size distribution control of the plate-like BaTiO3 template

High-strain piezoelectric ceramics are required to miniaturize actuators for use in machinery and electronic systems. This paper reports an ultra-high strain of textured Pb(Mg1/3Nb2/3)O3–PbZrO3–PbTiO3 (PMN–PZ–PT) ceramics prepared using a plate-like BaTiO3 (BT) template. Small BT particles (<5 µm), which are difficult to orient as desired during tape casting, were removed from the as-synthesized BT (as-BT) template via a simple sedimentation method. Then, the residual BT (rs-BT) was used to prepare textured PMN–PZ–PT ceramics, which were compared with the textured ceramics prepared using the as-BT. Results show that the textured 0.4PMN–0.22PZ–0.38PT ceramics prepared with 5 vol% of rs-BT yield a significantly enhanced unipolar strain of 0.26% at 2 kV mm−1, when compared to the strain of 0.21% obtained from the textured 0.4PMN–0.22PZ–0.38PT ceramics prepared with the same amount of as-BT.

Ferroelectric and piezoelectric properties of BaTiO3-templated 0.36BiScO3-0.64PbTiO3 thick films for piezoelectric device applications

ABSTRACT A novel 0.36BiScO3-0.64PbTiO3 (0.36BS-0.64PT) textured ceramic was developed using plate-like BaTiO3 (BT) templates for high temperature piezoelectric device applications. Sintering temperature and amount of BT template played important roles in improving the density, crystal orientation, and ferroelectric and piezoelectric properties of the BT-templated 0.36BS-0.64PT thick films. When sintered at 1000°C, highly dense BS-PT textured films were obtained without formation of a secondary phase. The increased amount of BT template facilitated the degree of texture but deteriorated the relative density of BS-PT thick film. In particular, enhanced ferroelectric and piezoelectric properties were obtained for 1 vol% BT-templated 0.36BS-0.64PT thick film sintered at 1000°C; this film exhibited the very large Pr (44.2 μC/cm2 at 4 kV/mm), d33 (444 pC/N), kp (57.4%), and g33 (36 × 10−3Vm/N) values. In addition, considering the inverse relation between TC and strain, the electrostrain of d33* (622 pm/V at 4 kV/mm) was excellent, showing potential for piezoelectric actuator applications.

Optimisation of matrix composition for texturing of morphotropic phase boundary Pb(Mg1/3Nb2/3)O3–PbZrO3–PbTiO3 piezoelectric ceramics using BaTiO3 template

Texturing is an innovative method for fabricating high-performance piezoelectric ceramics. However, the optimal conditions for successful texturing must be evaluated to obtain high performance. Herein, the texturing behaviour of Pb(Mg1/3Nb2/3)O3–PbZrO3–PbTiO3 (PMN–PZ–PT) piezoelectric ceramics using plate-like BaTiO3 crystals as a template was found to be strongly dependent on the chemical composition of the matrix. Given that the solubility of BaTiO3 in the matrix increased with the PZ content, an excessive amount (>20 mol%) of the BaTiO3 template was necessary for texturing a 0.2PMN–0.38PZ–0.42PT, while 3 mol% of the BaTiO3 template could texture a 0.4PMN–0.22PZ–0.38PT. Owing to well-aligned textured grains and the complete consumption of randomly oriented matrix particles, a textured 0.4PMN–0.22PZ–0.38PT sample prepared by tape-casting under optimised conditions yielded a Lotgering factor of 97 % and an induced strain of 0.2 % with an electric field of 2 kV/mm.

Design and development of high-power piezoelectric ceramics through integration of crystallographic texturing and acceptor-doping

This study demonstrates the integrated approach based upon texturing and acceptor doping for realizing a high-power piezoelectric ceramic with combined soft and hard properties. The textured Mn-doped 0.24 Pb(In1/2Nb1/2)O3-0.42 Pb(Mg1/3Nb2/3)O3-0.34 PbTiO3 (PIN-PMN-PT) ceramic exhibits enhanced piezoelectric coefficient d33 and electromechanical coupling factor k31 in comparison with random counterpart. This enhanced piezoelectric response originates from the combined intrinsic high piezoelectric properties of <001>-oriented grains, and reduced energy barrier for polarization rotation in textured ceramics. The BaTiO3 (BT) template in textured ceramics increases the tetragonality degree which results in improved coercive field Ec but decreased mechanical quality factor Qm in comparison with random counterpart. The decreased Qm values of textured ceramics are related to the crystallographic dependence of Qm and the enhanced domain mobility due to the existence of small size domains. The textured ceramic with 2 vol.% BT content exhibited an excellent combination of soft and hard piezoelectric properties, measured to be: d33 = 517 pC/N, Qm = 1147, Ec = 10.0 kV/cm, and tan δ = 0.49%, which is highly promising for high power piezoelectric applications.

Investigation of the piezoelectric and anti-reduction properties of (Ba, Ca) (Ti, Sn, Hf) textured ceramics prepared under low oxygen partial pressure conditions at low sintering temperatures

Multilayer piezoelectric ceramics must be sintered in a reducing atmosphere, preventing oxidation of the inner base metal. Plate-like textured (Ba, Ca)(Ti, Sn, Hf)O3 ceramics with a <001> preferred orientation were successfully developed at a low oxygen partial pressure (PO2:10−8 atm) using a BaTiO3 (BT) template with sintering temperatures < 1300 °C, which is beneficial for multilayer applications using base metal co-firing with ceramics. When adding the 3 wt% BT template, the proposed samples had a Lottgering factor of 84 %, piezoelectric coefficients d33 = 324 pC/N, -d31 = 122 (pC/N), and Qm = 452, and the strain values increased from 0.07 % for the randomly oriented ceramics to 0.115 % at 20 kV/cm for the textured ceramics, confirming that the texturing behavior assisted the grain growth and improved both the soft and hard behaviors and insulation resistance of the proposed lead-free ceramics. These findings make a significant contribution to the production of high-power piezoelectric components.

Formation mechanism of barium titanate single crystalline microplates based on topochemical transformation using bismuth-based precursors

Owing to their importance in applications related to textured ceramics engineering, two-dimensional perovskite single-crystal microplates are highly desirable. In this work, (001)-oriented perovskite-structured BaTiO3 (BT) single-crystal microplatelets were fabricated from an Aurivillius-structured BaBi4Ti4O15 precursor via topochemical transformation. XRD, SEM, DTA, and TEM characterizations were performed to investigate the crystallization behavior and morphology evolution of the product at different reaction stages, with a focus on the formation mechanism of BT single crystalline microplatelets. Our results indicate that secondary recrystallization repaired the significant micro-structural/crystalline damage that was caused, thereby preserving the single-crystal structure during structural conversion. The subsequent epitaxial growth and replenishment through Ostwald ripening resulted in more regular shapes and narrower distributions of BT microplatelets. This study not only suggests suitable BT template candidates for the application of textured ceramics, but also provides new insights into a simple topochemical transformation strategy for manufacturing two-dimensional perovskite microcrystals.

Texture tolerance to B-site valence mismatch for [001] textured Pb97.5%Ba2.5%[(Zn1/3Nb2/3) (1-x)–Tix]O3 transparent ceramics

Transparent Pb97.5%Ba2.5% [(Zn1/3Nb2/3) (1-x)–Tix]O3 ceramics have been textured using BaTiO3 template. The influence of B-site valence mismatch between the host and the template on texture growth is investigated. The texture degree depends on the Ti4+ content in the host. The minimum Ti4+ content of 9% is necessary for texture growth. X composition in the vicinity of 9% is demonstrated at MPB where the maximum d33 and kp is 660 pC/N and 63%, and a strain as high as 0.27% at 40 kV/cm is achieved. The transmittance of textured P97.5%B2.5% (ZN–4%T) ceramic is 47% at 600 nm and exceeds 60% at the wave length of 1000–3000 nm. This research gives a better understanding of texture growth and facilitates the designs of multi-functional devices.

Effect of texture on the electrical and electrocaloric properties of 0.90Pb(Mg1/3Nb2/3)O3–0.10PbTiO3 relaxor ceramics

Functional properties of ferroelectric compositions depend strongly on the type of stable crystalline phase at a given temperature and texturing. In addition to defining a governing crystallographic axis among the grains with respect to a global reference axis, texturing in these systems is also often meant to imply the relationship between an external applied field and the polar axis. Here, we synthesize randomly oriented and ⟨001⟩pc textured 0.90Pb(Mg1/3Nb2/3)O3–0.10PbTiO3 solid solutions that fall into the relaxor category. A &amp;gt;95% degree of ⟨001⟩pc texturing was achieved by the use of single crystal BaTiO3 template crystallites whose volume fraction does not exceed 5% of the entire sample volume. Electrical measurements made on random and textured samples reveal the impact of texture on the hysteresis and the dielectric response. A Curie–Weiss analysis of the temperature dependent dielectric data shows the degree of relaxor behavior in random and textured samples. As similar compositions have recently been getting interest for electrothermal management applications, we compute the electrocaloric (EC) response of the random and textured samples using indirect methods followed by an estimation of the EC response with a subsequent thermodynamic analysis to shed light on the effect of texture on the observed differences between the textured and the random oriented samples. We finally compare and contrast on the desirability of texturing in these systems for use as EC components for thermal management applications.

High‐Performance [001]c‐Textured PNN‐PZT Relaxor Ferroelectric Ceramics for Electromechanical Coupling Devices

Abstract[001]C‐Textured 0.55Pb(Ni1/3Nb2/3)O3–0.15PbZrO3–0.3PbTiO3 (PNN‐PZT) ceramics are prepared by the templated grain‐growth method using BaTiO3 (BT) platelet templates. Samples with different template contents are fabricated and compared in terms of texture fraction, microstructure, and piezoelectric, ferroelectric and dielectric properties. High piezoelectric performance (d33 = 1210 pC N−1, d33* = 1773 pm V−1 at 5 kV cm−1) and high figure of merit g33⋅d33 (21.92 × 10−12 m2 N−1) are achieved in the [001]C‐textured PNN‐PZT ceramic with 2 vol% BaTiO3 template, for which the texture fraction is 82%. In addition, domain structures of textured PNN‐PZT ceramics are observed and analyzed, which provide clues to the origin of the giant piezoelectric and electromechanical coupling properties of PNN‐PZT ceramics.

Enhancement of electrical properties in the ternary PMN–PT–PZ through compositional variation, crystallographic texture, and quenching

AbstractTernary compositions of Pb(Mg1/3Nb2/3)O3–PbZrO3–PbTiO3 (PMN–PZT) piezoelectric ceramic have been investigated with an aim to optimize the electrical properties for piezoelectric applications. Quenching from temperatures above the Curie point was proved to enhance the properties up to two folds in the 0.40PMN–0.25PZ–0.35PT composition. This enhancement is believed to have arisen as a result of the freezing of defect dipoles in their random distribution, and thus prevention of their domain pinning effect. Texturing the optimum composition using BaTiO3 template particles through templated grain growth process and quenching the textured ceramic led to further enhancement with piezoelectric charge coefficient increasing from 190 to 750 pC/N, relative permittivity increasing from 860 to 1815 and remanent polarization increasing from 16 to 30 μC/cm2.

Effect of Different Templates on Electrical Properties of Textured KNN-Based Ceramics

Platelike and perovskite structure NaNbO3 (NN) with orthorhombic, SrTiO3 (ST) with cubic and BaTiO3 (BT) with tetragonal were used as templates to fabricate grain-oriented 0.94(K0.5Na0.5)NbO3-0.06LiSbO3 (0.94KNN-0.06LS) ceramics by templated grain growth (TGG). The effects of different templates on the grain orientation, ferroelectric, dielectric, piezoelectric properties and strain behavior of 0.94KNN-0.06LS ceramics were systematically investigated. Textured ceramics with high orientation factor were obtained successfully when the platelike NN was used as a template, while high degree of grain orientation cannot be obtained with ST and BT template. The templated growth of <00l> oriented grains on the NN template resulted in textured ceramics with brick significantly high <00l> texture degree corresponding to 87% Lotgering factor at 5 mol% NN templates. Textured ceramics with NN templates exhibited excellent piezoelectric properties as compared to the random counterparts due to high degree of grain orientation, while ceramics used ST templates shown excellent strain behavior.

Enhanced temperature stability in 〈111〉 textured tetragonal Pb(Mg1/3Nb2/3)O3-PbTiO3 piezoelectric ceramics

Two different templates (〈001〉 Ba6Ti17O40 and 〈111〉 BaTiO3) were used for synthesizing 〈111〉 textured tetragonal 0.6Pb(Mg1/3Nb2/3)O3-0.4PbTiO3(PMN-40PT) ceramics. It was found that a texture degree of 95% along 〈111〉 direction can be achieved by using only 1 vol. % 〈111〉 BaTiO3 template due to its high chemical stability in the PMN-40PT matrix. The textured PMN-40PT ceramics with tetragonal structure exhibited an excellent temperature stability of piezoelectric properties due to the absence of intermediate phase transitions between room temperature and the Curie temperature. Unlike the single crystal counterpart, the effect of 〈111〉 grain orientation in the textured PMN-40PT ceramic on enhancing the macroscopic piezoelectric response was not significant in spite of its giant local piezoresponse. We provide detailed discussions on the nature of piezoelectric response in the 〈111〉 textured tetragonal PMN-40PT ceramic with “3T” engineered domain configuration and resultant strategy to realize high performance piezoelectric ceramics.

Enhanced electromechanical properties and phase transition temperatures in [001] textured Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ternary ceramics

[001] oriented relaxor based ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ceramics were fabricated by templated grain growth. The effects of BaTiO3 template amount on the [001] orientation degree, microstructure, and resulting changes in dielectric, piezoelectric, and ferroelectric properties of PIN-PMN-PT were investigated. A high [001] texture fraction of 93% was achieved in the PIN-PMN-PT ceramics at 5 vol. % BaTiO3 template. Giant electromechanical properties (d33* = 1555 pC/N, d33 = 824 pC/N, and kp = 0.81) and high ferroelectric properties (Ec = 8.3 kV/cm and Pr = 31 μC/cm2) were obtained from those highly textured ceramics, which are much superior to those of randomly oriented counterpart. Furthermore, the textured ternary ceramics exhibited remarkably improved phase transition temperatures (Tr-t = 120 °C and Tc = 203 °C) compared with previously reported binary PMN-PT textured ceramics. The domain structure was characterized by piezoelectric force microscopy, and domain contribution to the enhanced piezoelectric response in the textured PIN-PMN-PT ceramics was analyzed. The high-quality textured ternary ceramics are very promising for new-generation electromechanical devices with high performance and wide temperature usage range.

Effect of different templates on structure evolution and large strain response under a low electric field in -textured lead-free BNT-based piezoelectric ceramics

<00l>-textured 0.83Na0.5Bi0.5TiO3–0.17Bi0.5K0.5TiO3 (BNT–BKT) ceramics with high degree of texturing (>80%) were synthesized by templated grain growth using different perovskite plate-like BaTiO3, SrTiO3 and NaNbO3 as template particles to develop lead-free piezoelectric materials with an excellent actuating performance. The effects of different template particles addition to BNT–BKT ceramics on the grain orientation, structure evolution, phase stability and macroscopic functional properties was systematically investigated. BaTiO3 template particles addition to form <00l>-textured BNT–BKT–BT textured ceramics suppresses an electric-field-induced long-range ferroelectric order, giving rise to a high field-induced Smax/Emax of 710pm/V under a relatively low driving field of 45kV/cm compared with existing lead-free Bi-perovskite ceramics. In particular, temperature-dependent strain response reveals that <00l>-textured BNT–BKT–5BT ceramics exhibit not only large Smax/Emax at a low driving field of 45kV/cm at room temperature but also enhanced the temperature stability of Smax/Emax featured by large Smax/Emax of 517pm/V at high temperature.

Synthesis of (111) textured lead-free piezoelectric ceramics through template grain growth process

P devices in consumer applications are being required to eliminate the lead due to its toxic nature to human health. This has led to significant emphasis on the development of lead-free piezoceramic materials that can match performance of current lead-based compositions. However the performance of all the known lead free remains inferior. A promising approach for enhancing the piezoelectric shear d15 response of lead-free piezoceramics is to synthesize the (111) grain oriented material by using the template particles with high (111) crystallographic orientation. In this work, we report the synthesis of (111) oriented BaTiO3 (BT) template particles and their application towards deriving the (111) textured leadfree piezoelectric ceramics. BT particles were synthesized by two-step molten salt synthesis method (MSS) from plate-like Ba6Ti17O40 (B6T17) precursor through topochemical microcrystal conversion (TMC) method. In order to identify the largest developed planes of the TMC-synthesized BT particles, X-ray diffraction measurement technique (OPL-XRD) was applied. The prepared BT particles were embedded in the slurry and then subjected to the tape casting. During casting, the templates are aligned by shear force in the preferred orientation. The samples were found to exhibit higher intensity for the (111) Bragg reflection in the XRD spectra suggesting good orientation of BaTiO3 particles along the direction. These (111) oriented BT templates were next used for synthesizing (111) grain oriented lead-free piezoelectric ceramics.