Piezoelectric and Dielectric Properties of Pb(Zr x Ti1 − x )O3-Pb(Ni1/3Sb1/3Nb1/3)O3 Piezoelectric Ceramics

In this paper, piezoelectric and dielectric properties of 0.9PbZr_xTi_1–xO₃-0.1PbNi_1/3Sb_1/3Nb_1/3O₃ were studied as a function of Zr/Ti mole ratio(x) for application to piezoelectric actuator. Also, microstructure and crystalline phase are investigated by using SEM and XRD, respectively. As a results, the substitution of Sb5+ to B-site increases the piezoelectric and dielectric properties, and when Zr/Ti mole ratio is 49/51 and ternary mole ration is 0.1(0.9PbZr_0.49Ti_0.51O₃-0.1PbNi_1/3Sb_1/3Nb_1/3O₃), the corresponding composition were found belonging to the Morphotropic Phase Boundary region with electromechanical coupling coefficient(k_p), mechanical quality factor (Q_m), permittivity(_r) and piezoelectric strain constant(d₃₃) equaled to 63%, 360, 2000 and 470 pC/N, respectively. Sintering temperature was about 1150_C and Curie temperature was determined around 290_C.     

Synthesis and Dielectric Characterization of Pyrochlore-Free Pb1−x Ba x (Zn1/3Nb2/3)O3 Ceramics

The dielectric properties and synthesis of pyrochlore-free lead zinc niobate ceramics with Ba substituting for Pb were investigated. Ba partial substitution for Pb was effective in stabilizing the perovskite structure in PZN ceramics, where the minimum amount of Ba substitution needed was about 20 mol%. The dielectric loss and the temperature coefficient of dielectric constant of PZN were reduced markedly with Ba substitution, while the dielectric constant was greater than 110. Good dielectric properties were obtained for the composition of Pb_0.3Ba_0.7(Zn_1/3Nb_2/3)O₃: = 133.5, tan = 0.0009, = –811 ppm/°C.     

Dielectric Properties of Bi4−x La x Ti3O12 (0 ≤ x ≤ 2) Ceramics

The dielectric properties of the Bi_4–x La _x Ti₃O₁₂ (0 x 2) ceramics were characterized and discussed together with the P-E relation (polarization vs. electric field). With increasing x, the P-E relation changed from normal ferroelectric hysteresis loops to pure linear relation, which indicated that La³⁺ substitution for Bi³⁺ in Bi₄Ti₃O₁₂ induced a phase transition from ferroelectric to paraelectric state at ambient temperature. Low loss dielectric ceramics with temperature stable dielectric constant were obtained for x > 1.2 in Bi_4–x La _x Ti₃O₁₂ at 1 MHz. And the loss increased in all the compositions when the ceramics were measured at microwave frequencies.     

Microwave Dielectric Properties of Ferroelectric Pb(Zr1 − x Ti x )O3 Thin Films Using Interdigital Capacitors

Ferroelectric Pb(Zr_{1 ? x} Ti _x )O₃ (PZT) films were deposited on (001) MgO single crystals using sol-gel method. Structural properties and surface morphologies of PZT films were investigated using an X-ray diffractometer and a scanning electron microscopy, respectively. The dielectric properties of PZT films were investigated with the dc bias field of 0–135 kV/cm using interdigitated capacitors (IDC) which were fabricated on PZT films using a thick metal layer by photolithography and etching process. The small signal dielectric properties of PZT films were calculated by a modified conformal mapping method with low and high frequency data, such as capacitance measured by an impedance gain/phase analyzer at 100 kHz and reflection coefficient (S-parameter) measured by a HP 8510C vector network analyzer at 1–20 GHz. The IDC on PZT films exhibited about 67% of capacitance change with an electric field of 135 kV/cm at 10 GHz. These PZT thin films can be applied to tunable microwave devices such as phase shifters, tunable resonators and tunable filters.     

Effect of B2O3 Nano-Coating on the Sintering Behaviors and Electrical Microwave Properties of Ba(Nd2 − x Sm x )Ti4O12 Ceramics

Ba(Nd_0.8Sm_0.2)₂Ti₄O₁₂ ceramics prepared by conventional solid-state sintering have a dielectric constant of about 80 and a nearly zero temperature coefficient of resonant frequency; however, the sintering temperature is above 1350_C. Doping with B₂O₃ (up to 5 wt%) promotes the densification and dielectric properties of BNST ceramics. It is found that coating BNST powder with thin B₂O₃ layer of about 180 nm reduces the sintering temperature to below 1020_C. The effects of B₂O₃ nano-coating on the dielectric microwave properties and the microstructures of BNST ceramics are investigated. Ninety-six percent of theoretical densities is obtained for specimens coated with 2 wt% B₂O₃ sintered at 960_C and the samples exhibit significant (002) preferred orientation and columnar structure.     

Scaling Effect on the Dielectric Constant in Ba(Ti x Zr1−x )O3 Thin Films

Recent work on PZT and BST thin films reveal a thickness dependence of the dielectric constant for a film thickness below 100 nm. This effect is commonly attributed to an interfacial layer between the electrode and the dielectric film (dead layer). In this contribution we report on the influence of the film thickness on the dielectric constant of Ba(Ti_xZr_{1 – x})O₃ thin films with different Zr-contents (x = 0–30 at.%). The films were prepared by chemical solution deposition (CSD) with thickness between 30 and 350 nm.The electrical characterization was performed in a temperature range between 25 and 200C. Results were interpreted with respect to the formation of a serial dead layer capacitance.     

Investigation of dielectric and relaxor ferroelectric properties in Ba(Zr x Ti1−x )O3 ceramics

Barium zirconate titanate Ba(Zr _x Ti_1?x )O₃ (BZT x?=?0.1, 0.15, 0.2, 0.25) ceramics doped with Nb₂O₅ have been prepared by a traditional solid phase reaction. The temperature dependence of dielectric permittivity has been investigated. The results show that the phase transition temperature T _c is depressed and the diffuse phase transition behavior is enhanced with increasing Zr content. The Cole–Cole plot has been discussed and the cause of the deviation has been analyzed. The temperature dependence of inverse dielectric constants was investigated. A modified Curie–Weiss law can be used to describe the diffuseness of a phase transition, and diffusion factor increases with the Zr content.     

Temperature-Stable High-ε Dielectrics Ceramics Based on (1 − x) Ba5NdTi3Ta7O30/xBi4Ti3O12

Modification of Ba₅NdTi₃Ta₇O₃₀ dielectric ceramics was investigated through introducing Bi₄Ti₃O₁₂. With increasing of Bi₄Ti₃O₁₂ content, the dielectric constant increased, and the temperature coefficient of the dielectric constant changed from negative to positive. The small temperature coefficient ( < 50 ppm/°C) combined with high dielectric constant ( = 178) and low dielectric loss (tan = 0.007 at 1 MHz) was achieved in the composition x = 0.6.     

Ferroelectric Properties of Pb(Zr1 − x,Tix)O3 Prepared by Modified Metallo-Organic-Decomposition Process

Beneficial effect of nano-sized PZT powder incorporation on modifying the characteristics of Pb(Zr_0.52Ti_0.48)O₃, PZT films was demonstrated. The amorphous phase derived from metallo-organic-decomposition (MOD) process started to crystallize at a post-annealing temperature as low as 500°C and can withstand 650°C post-annealing temperature process without inducing the PbO-loss phenomenon. However, 500°C post-annealed PZT films still exhibit paraelectric properties, which can be ascribed to the co-existence of large proportion of amorphous phase, surrounding the crystalline phase. It needs at least 650°C post-annealing process to fully developed the pervoskite structure for PZT films. The remnant polarization (Pr) of the PZT films increases with the proportion of crystalline phase, achieving Pr = 24.9 μC/cm² for 650°C annealed films, with coercive field (Hc) around Ec = 373 kV/cm.     

Properties of CaTi1 − x Fe x O3 − δ Ceramic Membranes

CaCO₃, TiO₂ and Fe₂O₃ were mixed in the appropriate stoichiometric quantities and calcined at 1100C for 10 h. These powder mixtures were uniaxially pressed and sintered at temperatures ranging from 1350 to 1500_C for 2 h in order to obtain dense disk-shaped samples with nominal CaTi_{1 – x}Fe_xO_3– (x = 0.05, 0.15, 0.20, 0.40 and 0.60) compositions. Dilatometry and in situ high temperature powder X-ray diffraction analysis showed a good agreement on the thermal expansion behaviour of these materials between room temperature and 1000_C. The estimated linear thermal expansion coefficient is close to 13× 10^{– 6} K^{– 1} and is little affected by composition. No evidence for surface carbonation was detected in the infrared spectra collected on samples previously annealed in CO₂ atmospheres. The oxygen permeability measured at temperatures ranging from 750 to 1000_C goes through a sharp maximum for x = 0.20. This result is interpreted by structural differences related to change from disordered to ordered oxygen vacancies. The overall performance of CaTi_0.80Fe_0.20O_3– is compared to other mixed conducting materials.     

Perovskite phase formation in sol-gel derived Pb(ZrxTi1−x)O3 thin films

Abstract

Thin films of lead zirconate titanate having the composition Pb_1.05(Zr_0.53Ti_0.47)O₃ were deposited by a solgel method on a set of crystalline and amorphous substrates. The thickness of the film was varied by controlling the sol concentration or by repeated coatings. Factors controlling phase formation in the films such as nature of the substrate material, film thickness, chemical composition of the film, heating rate and gaseous atmosphere during the heat treatment were studied. On glass substrates the pyrochlore phase was obtained in thin (0.4 um) films and the perovskite phase in thicker (>1.5 um) films. Crystalline substrates (except Si and stainless steel) yielded a perovskite phase in 0.6 um thick film. Low Zr/Ti ratio, rapid heating and introduction of nitrogen in the later stage of heat treatment also favoured the formation of the perovskite phase. It is shown that Pb deficiency in the film caused by diffusion of Pb into amorphous substrates or by other mechanisms is primarily responsible for inhibiting the pyrochlore to perovskite transformation. The initial crystallisation of the amorphous film into pyrochlore rather than a perovskite phase (as in powders) is proposed to be due to higher strain energy barrier which exists for the amorphous to perovskite transformation in the film.     

Pb(Mg1/3Nb2/3)O3 and (1 − x)Pb(Mg1/3Nb2/3)O3 − xPbTiO3 Relaxor Ferroelectric Thick Films: Processing and Electrical Characterization

The lead magnesium niobate [Pb(Mg_1/3Nb_2/3)O₃ or PMN], and its solid solutions with lead titanate (PbTiO₃ or PT), are of great interest because of their high electromechanical properties. At large PMN content, these materials exhibit relaxor characteristics with large electrostrictive strains and a large permittivity, while compositions near the morphotropic phase boundary present very interesting piezoelectric properties. So far, properties of these materials in ceramic, thin film and single-crystal form have been investigated. In this paper, we report on preparation and properties of pyrochlore free PMN and 0.65PMN-0.35PT thick films (thickness = 10 to 20 m). The films were prepared from ethyl cellulose ink by screen printing on alumina substrate. The influence of various parameters, such as powder characteristics, inks formulation and films sintering conditions, on films densification are discussed. The dielectric and electromechanical properties of the films were examined. Relaxor-like behaviour was clearly demonstrated in PMN films. The maximum relative permittivity for PMN film was 10000 (at 0.1 kHz), which is lower than in bulk ceramics (17800 at 0.1 kHz) prepared under the same conditions. For 0.65PMN-0.35PT, the maximum relative permittivity was around 15500 against 24000 in the bulk. Several parameters, which might be responsible for the lower permittivity, are discussed. Poled 0.65PMN-0.35PT thick films exhibit relatively large piezoelectric response (d ₃₃ up to 200 pm/V) and unipolar strains approaching 0.1%, making these films of interest for various actuator and transducer applications.     

DIELECTRIC AND PIEZOELECTRIC CHARACTERISTICS OF 0.07Pb (Mn1/3Nb2/3) O3 −0.10Pb (Ni1/3Nb2/3) O3− 0.83Pb(Zr0.48Ti0.52) O3 CERAMICS ACCORDING TO THE HEATING RATE

ABSTRACT

In this study, in order to develop the composition ceramics for low loss multilayer piezoelectric actuator, 0.07Pb (Mn_1/3Nb_2/3) O₃ ?0.10Pb (Ni_1/3Nb_2/3) O₃? 0.83Pb(Zr_0.48Ti_0.52) O₃ (abbreviated as PMN-PNN-PZT) ceramics were fabricated using Li₂CO₃, Bi₂O₃ and CuO as sintering aids and according to variation of heating rate. And also, their dielectric and piezoelectric properties were investigated. At the heating rate of 700°C/h and sintering temperature of 900°C, density, electromechanical coupling coefficient (kp), mechanical quality factor (Qm), dielectric constant (ε _r ) and piezoelectric constant (d₃₃) of PMN-PNN-PZT ceramics showed the excellent values of 7.67 g/cm³, 0.58, 1199, 1560 and 380 pC/N, respectively for low loss multilayer piezoelectric actuator application.     

Effect of Mg doping on dielectric properties of sol-gel derived (Pb0.7Sr0.3)Mg x Ti1–x O3–x thin film

(Pb_0.7Sr_0.3)Mg _x Ti_1–x O_3–x (x?=?0?～?0.3) thin films were successfully prepared on ITO/glass substrate by sol-gel technique. The crystalline phase structures were measured through X-ray diffraction (XRD). The dielectric properties were measured by a precision impedance analyzer. Results show that the perovskite phase was stable in (Pb_0.7Sr_0.3)Mg _x Ti_1–x O_3–x thin film. Its lattice constant was found to decrease with the increase of x when x?<?0.1 and increase when x?>?0.1.The crystalline phase formation and the dielectric properties of the (Pb_0.7Sr_0.3)Mg _x Ti_1–x O_3–x thin film depend on Mg doping content. The phase formation ability was decreased below x?=?0.1 and then increased above x?=?0.1 with the increase in x. The dielectric constant of the thin film is correspondingly changed. The tunabilities of about 35%?～?63% were obtained at 10 kHz. The highest tunability and the lowest dielectric loss of the thin films appeared at x?=?0.2. The FOM of the thin film with Mg doping of x?=?0.2 is about three times higher than that of x?=?0.1 under applied frequency of 10 kHz.     

Piezoelectric and dielectric characteristics of low-temperature-sintering Pb(Mg1/2W1/2)O3–Pb(Ni1/3Nb2/3)O3–Pb(Zr,Ti)O3 ceramics according to the amount of PNN substitution

In this study, in order to develop low-temperature-sintering ceramics for multilayer piezoelectric actuator, Pb(Mg_1/2W_1/2)O₃–Pb(Ni_1/3Nb_2/3)O₃–Pb(Zr,Ti)O₃ (abbreviated as PMW–PNN–PZT) ceramics were fabricated using Li₂CO₃ and CaCO₃ as sintering aids and their dielectric and piezoelectric properties were investigated with the amount of Pb(Ni_1/3Nb_2/3)O₃ (abbreviated as PNN) substitution. PMW–PNN–PZT composition ceramics could be sintered up to 870°C by adding sintering aids. At the sintering temperature of 900°C, electromechanical coupling factor (k _p), piezoelectric constant (d ₃₃) and Curie temperature (Tc) in the composition ceramics with 9 ;mol% PNN substitution showed the optimal value of 0.64 517 ;pC/N and 317°C, respectively for multilayer actuator application.     

Low-temperature sintering and dielectric properties of the Bi(Nb1−x Ta x )O4 system

Low-temperature sintering and dielectric properties of the Bi(Nb_1?x Ta _x )O₄ (x?=?0.1, 0.3, and 0.5) system was investigated as a function of the zinc borosilicate (ZBS) glass content with a view to applying this system to LTCC technology. The addition of 7 wt% ZBS glass ensured a successful sintering below 900°C. The complete solid solution of Bi(Nb, Ta)O₄ with an orthorhombic structure was formed and the high temperature form of Bi(Nb, Ta)O₄ with a triclinic structure was not observed. The second phase of Bi₂SiO₅ was observed for all compositions. The non-relative liquid phase sintering (NLPS) occurred and the one-stage sintering was conducted. The Q?×?f values were improved by the addition of Ta. Bi(Nb_0.7Ta_0.3)O₄ with 7 wt% ZBS glass sintered at 900°C demonstrated 35.8 in the dielectric constant (? _r), 2,200 GHz in the quality factor (Q?×?f ₀), and ?48 ppm/°C in the temperature coefficient of resonant frequency (τ _f).     

Development of ferroelectric Pb(ZrxTi1−x)O3 thin films by metallo-organic decomposition process and rapid thermal annealing

Polycrystalline Pb(Zr_0.5Ti_0.5)O₃ thin films with good ferroelectric properties have been prepared by metallo-organic decomposition (MOD) process, using acetate-based precursors, and followed by two different kinds of annealing process, independently, including oven annealing and rapid thermal annealing (RTA). The experimental procedures were described for the films deposited on Pt-coated silicon substrates. There were distinct differences between oven annealing and RTA process, in terms of structures, morphologies, and electrical properties of the films. The films with RTA process showed denser and smoother surface, finer grain sizes, and much higher dielectric constant (1200–1400), remnant polarization of 30–35 μC/cm² and lower coercive field of 65–85 kv/cm in the entire annealing temperature range of this study. At an annealing temperature of 550°C, RTA processed films showed identical XRD patterns of perovskite phase and clear ferroelectricity; however, it was not possible to realize the perovskite structure and ferroelectricity in the films oven-annealed at that temperature. These acetate-derived PZT films with RTA process were reproducible, showed high quality in uniformity and homogeneity.     

Piezoelectric properties of the high temperature MPB xPbTiO3 - (1−x)[BiScO3 + Bi(Ni1/2Ti1/2)O3] composition

The ternary perovskite xPbTiO₃ - (1?x)[BiScO₃ + Bi(Ni_1/2Ti_1/2)O₃] (PT-BS-BNiT), where x?=?0.54 is the morphotropic phase boundary composition, was studied for high temperature ferroelectric applications. Polycrystalline ceramics were prepared using the standard solid-state methods. The stoichiometric ceramic was found to have room temperature dielectric permittivity and loss values at 1 kHz of 1490 and 0.049 respectively. Piezoelectric properties, of the stoichiometric composition, measured included: P_r?=?31.0 μC/cm², E_c?=?25.0 kV/cm, d₃₃?=?340 pC/N, d₃₃ ^*?=?896 pm/V, and a bipolar electromechanical strain of 0.25 %. From these data, the Curie temperature was T_C?=?370 °C and the depoling temperature was T_D?=?325 °C. Processing ceramics with excess bismuth improved the low field piezoelectric coefficients with a maximum of d33?=?445 pC/N, while increasing the lead content increased the transition temperatures. The depoling and Curie temperatures of all compositions were measured to be between 275 and 400 °C.     

Synthesis and Ferroelectric Response of Bi 4−x Nd x Ti 3 O 12 Thin Films

Nd doped Bi 4 Ti 3 O 12 layered materials were synthesized using a solution chemistry route. Thin films were deposited by spin coating. Powder and thin film samples were characterized by x-ray diffraction and Raman spectroscopy. Ferroelectric response of Bi 4 m x Nd x Ti 3 O 12 thin film (x = 0.95), deposited on Pt substrate is reported.     

Piezoelectric characteristics of low temperature sintering Pb(Ni1/3Nb2/3)O3–Pb(Zr1/2Ti1/2)O3 ceramics as a function of Pb(Mn1/3Sb2/3)O3 substitution

In this study, in order to develop the composition ceramics for multilayer ceramic for ultrasonic nozzle and ultrasonic actuator application, Pb(Mn_1/3Sb_2/3)O₃ (abbreviated as PMS) substituted Pb(Ni_1/3Nb_2/3)O₃–Pb(Zr,Ti)O₃ (abbreviated as PNN-PZT) ceramics were fabricated using two-stage calcinations method and Li₂CO₃, Na₂CO₃ and ZnO as sintering aids, and their piezoelectric and dielectric characteristics were investigated. With the increase of the amount of PMS substitution, electromechanical coupling factor (k _p), and mechanical quality factor (Q _m) of specimens showed the maximum value at 3 mol% substituted specimen while dielectric constant (? _r) was decreased. At the sintering temperature of 900 °C, the density, ? _r, k _p, and Q _m of 3 mol% PMS substituted PNN-PZT composition ceramics showed the optimal values of 7.92 [g/cm³], 959, 0.584, and 1003, respectively, for low loss multilayer piezoelectric actuator application.