PZT Solid Solution Research Articles

Antiferroelectric Lead based Perovskite Material properties andapplications: A Review

In this review paper, the discussion is about some of the lead based antiferroelectric (AFE) perovskite materials. The antiferroelectric perovskite materials mainly lead zirconate (PZ) and lead zirconate titanate (PZT) prepared by solid state reaction route with their structure change at different concentrations, phase transition, their dielectric properties ormore. These materials caught the attention of the researchers because of their use in high energy storage devices, pyroelectric devices, sensors, cooling devices, pulse power generators and have many more applications. The reason could be their electric field phase transformation between the antiferroelectric (AFE) state and ferroelectric (FE) state and the phase switching property can be one of the strong factors responsible for the performance of the PZ based materials. Thecentral focus of this review is to briefly explain the continuous increase in research in the antiferroelectric materials by enhancing the PZ with many dopants. We mainly address PZ and PZT solid solution properties.

The Formation of Doped PZT Solid Solution and Its Structural Characterization

The main objective of this work is the synthesis, structural and morphological characterization of ceramics materials. Abbreviated PZT-PYN. Ferroelectric ceramics of general formulation Pb(ZrxTi1-x)O3 are massively used in many fields such as medicine or aeronautics because of their dielectric and electromechanical properties, although the electronic properties of doped PZT are much better compared to undoped PZT. Samples selected for this study were prepared bins solid way. The thermal treatment called calcination was applied to these compositions is carried around: 450℃, 550℃, 650℃, 750℃, and 900℃ for two hours with a Vitesse of 2℃ / min., then sintered at different temperatures: 1100℃, 1150℃, 1180℃, successively to optimize the sintering temperature where the product is better physical quality. Different techniques of characterization were used such as scanning electron microscopy (SEM), x-ray diffraction (XRD) analysis, and Energy-dispersive spectrometric, which showed that the response is optimal for the compositions included in the morphotropic phase boundary, achieves excellent properties.

Dielectric and energy storage characteristics of 0.2, 0.4, 0.6, 0.8 wt% Cr2O3 doped PbZr0.52Ti0.48O3 ceramics synthesized by spark plasma sintering

The microstructure, phase analysis, impedance and modulus spectroscopies, dielectric and energy storage characteristics have been carried out on Cr2O3 doped PbZr0.52Ti0.48O3 (PZT) ceramics. The PbZr0.52Ti0.48O3 + x Cr2O3 (x = 0.2, 0.4, 0.6 and 0.8 wt%) ceramics were synthesized by solid state reaction method following spark plasma sintering technique. The particle size of calcined powders lies between 200 nm and 500 nm, and the particles have largely faceted morphology. The analysis of X-rays diffraction patterns of the ceramics reveals perovskite structure with tetragonal lattice having P4mm space group. No additional peak related to Cr- based compound has been detected, which indicates Cr solubility in the PZT solid solution. The Cr2O3 doped PZT samples exhibit ≥ 99.3 % relative density with average grain size lower than that of undoped PZT samples reported. The peak value of dielectric permittivity (εm) was found to decrease when the Cr2O3 content is above 0.2 wt%; however, it increases for 0.8 wt% Cr2O3 doped sample. Such behavior is explained based on the multivalent nature of chromium ions. The impedance and modulus spectroscopic analyses reveal the contributions of grain relaxation and confirm the non-debye type of relaxation. The modulus studies reveal the presence of hopping mechanism in the material. The DC conductivity curves show a typical Arrhenius type behavior of electrical conductivity. The energy storage studies reveal an increase in remnant polarization and coercive field for samples containing up to 0.6 wt% Cr2O3 and the results are in agreement with the XPS observations. The highest energy storage density (∼0.1 J/cm3) and efficiency (∼64%) under an electric field of 25 kV/cm were observed for 0.2 wt% and 0.8 wt% Cr2O3 doped PZT samples, which are attributed to the dominant presence of donor Cr5+ ion.

Ab initio modelling of the effects of varying Zr (Ti) concentrations on the atomic and electronic properties of stoichiometric PZT solid solutions

Lead zirconate titanate Pb(ZrxTi1−x)O3 solid solution is considered as one of the most advanced ferroelectric and piezoelectric materials. Consequent variation of Zr (Ti) concentrations significantly affects the atomic and electronic properties of PZT structures. To perform ab initio modelling of different morphologies for lead zirconate titanate, we are using approach of hybrid density functional B3PW as implemented in CRYSTAL14 computer code. In this study, we are performing large-scale calculations of such PZT parameters as optimized lattice constants, atomic charges and bond populations, as well as band structure (e.g., band gap) and density of states.

Structure, dielectric and piezoelectric properties of donor doped PZT ceramics across the phase diagram

ABSTRACTThe effects of Zr/Ti ratio on the dielectric and piezoelectric properties of the sintered Pb(ZrxTi(1−x))0.99Nb0.01O3 piezoelectric ceramics across the entire range of phase diagram of the PZT solid solution was studied systematically. The materials were prepared by the conventional mixed oxide process. The phase purity and crystal structure of the calcined powders and sintered ceramics was analysed using X-ray diffraction. The microstructure of the sintered ceramics has been investigated using scanning electron microscopy. It is seen that even though there is a significant increase in dielectric constant (ϵr) and piezoelectric charge coefficient (d33) at the PZT-52 (MPB) composition, the voltage sensitivity (g33) of the PZT-0 (lead titanate) ceramics are higher than that of MPB.

Phase structure–electrical property relationships in Pb(Ni1/3Nb2/3)O3–Pb(Zr,Ti)O3-based ceramics

Generally, the phase structure change of Pb(B′ B″)O3–PZT solid solutions near a morphotropic phase boundary (MPB) can be originated from composition variations. Here our results show that the excess PbO and the sintering temperature can also result in the ferroelectric phase structure change in the Pb(Ni1/3Nb2/3)O3–Pb(Zr,Ti)O3 (PNN–PZT)-based ceramics near the MPB. The dielectric, piezoelectric, and ferroelectric properties are dependent on the tetragonal phase content (TP) which is closely associated with the excess PbO and the sintering temperature. The temperature dependence of the polarization (P)–electric field (E) hysteresis loops reveals that the tetragonal phase in the PNN–PZT-based ceramics has a lower activation energy (Ea) for domain wall movement than that of the rhombohedral phase, thus resulting in easier polarization rotation. This is responsible for the phase structure–electrical property relationships in the PNN–PZT-based ceramics, exhibiting the dependence of the tetragonal phase content (TP) on the electrical properties.

Structural and electrical characterizations of Bi(Zn0.5Ti0.5)O3 doped lead zirconate titanate ferroelectric films with enhanced ferroelectric properties

Bi(Zn0.5,Ti0.5)O3 (BZT) doped Pb(Zr0.4,Ti0.6)O3 (PZT) films were fabricated using a chemical solution deposition method and were characterized intensively in the present work. It was discovered that the room temperature remnant polarization and zero-field longitudinal piezoelectric constant of the BZT-doped PZT film were enhanced by 23% and 30%, respectively, as compared with those of the undoped PZT film prepared under the same experiment conditions. In order to explain the improved ferroelectric properties, the phase structures of the BZT–PZT and undoped PZT films were experimentally investigated in a broad temperature range (from 30 to 600°C) by using the high temperature two-dimensional X-ray diffraction method. It was found that the improvement in ferroelectricity does not correspond to an elevated Curie temperature (TC) or a substantially larger tetragonality (c/a). The difference on the change of TC by doping of Bi-based perovskites in PZT solid solutions between this work and some previous investigations was explained on the basis of Zr/Ti ratio, and the necessity of an in-depth theoretical investigation was addressed.

Multiferroics application: Magnetic controlled piezoelectric transformer

Dense lead zirconate titanate (PZT) ceramics is typically used for fabrications of high power piezoelectric devices. In case of lanthanum and iron ions doping into PZT solid solution (PLFZT), material exhibiting both piezoelectric and magnetic properties can be obtained. Among many investigated compositions particularly the Pb0.91(La0.5Fe0.5)0.09(Zr0,65Ti0,35 )0,9775O3, located near the morphotropic boundary, exhibits the highest magnetoelectric effect. This coupling between magnetization and polarization is achieved by the Fe3+ ions addition that sufficiently rise sensitivity to magnetic field without decreasing the dielectric loss coefficient at the same time. Taking advantage of this specific material the piezoelectric transformer (PT) with magnetic feedback was fabricated, which converts an electrical AC input voltage into ultrasonic vibrations and reconverts back to an output as AC voltage proportionally to the magnetic field intensity. In the present study the unipoled radial mode piezoelectric transformers based on PLFZT-type ceramics prepared by hot-press sintering have been investigated. The effect of the magnetic field on the operating properties was measured for piezoelectric transformer operating at the first resonance frequency.

PLZT-based photovoltaic Piezoelectric Transformer with light feedback

Piezoelectric Transformer (PT) converts an electrical AC input voltage into ultrasonic vibrations and reconverts back to an output as AC voltage. Hard lead zirconate titanate (PZT) ceramics is typically used for fabrications of such devices. In case of lanthaniun ion La3+ addition in PZT solid solution we can achieve piezoelectric ceramics with good transparency exhibiting both optical Pockels and Kerr effects. Values of these coefficients in the PLZT system are much bigger than in LiNbO3 or SBN single crystals. Among the various PLZT compositions 8/65/35, near the morphotropic boundary, exhibit large electrooptic effect and thus have found applications in light shutters and displays. In the present study we have investigated radial mode piezoelectric transformer based on optically transparent PLZT8/65/35 ceramics. The effect of the UV light generated photovoltage and photostriction on the efficiency and voltage step-up ratio of piezoelectric transformer have been demonstrated. Novel functions of this device is proposed by superimposing two sophistically coupled effects of piezoelectricity and photostriction.

Dielectric and ferroelectric properties of Bi(Zn1/2Ti1/2)O3-PbTiO3-PbZrO3ternary ceramics

Ceramics of a new ternary solid solution system, xBi(Zn(1/2)Ti(1/2))O(3-yPbTiO(3)z)PbZrO(3) (xBZT-yPT-zPZ), with compositions along the solubility limit curve are prepared by solid-state reaction and sintering technique. Two morphotropic phase boundaries (MPBs) separating the orthorhombic and tetragonal (MPB(O-T)) phases and the tetragonal and rhombohedral (MPB(T-R)) phases, respectively, are observed with increasing z (0.10 ≤ x ≤ 0.21; 0 ≤ y ≤ 0.49). It is found that the transition from the ferroelectric to paraelectric phase becomes more diffuse with the addition of BZT into the PZT solid solution. Enhanced dielectric and ferroelectric properties appear at MPB(R-T), which exists over a wide composition region (0.45 ≤ z ≤ 0.6), as revealed by X-ray diffraction and dielectric measurements. The dielectric constant reaches a maximum value (ε' = 1250) on the tetragonal majority side of the MPB. The highest remnant polarization (P(r) = 34.2 μC/cm(2)) is found in the composition at the center of the MPB, where the rhombohedral and tetragonal phases coexist in almost equal quantities.

Effect of Bi( B)O 3 perovskite substitution on enhanced tetragonality and ferroelectric transition temperature in Pb(Zr,Ti)O 3 ceramics

The structure, dielectric properties, and Curie temperatures of Pb(Zr 1− x Ti x )O 3 doped with 5 mol% Bi(Zn 0.5Ti 0.5)O 3 (PZT–5BZT), 5 mol% BiFeO 3 (PZT–5BF), and 5 mol% BiAlO 3 (PZT–5BA) ceramics prepared by the conventional solid state reaction are reported. The structural phase transition temperature are compared with undoped and Bi( B)O 3 doped Pb(Zr 1− x Ti x )O 3 ceramics for 0.48 < x ≤ 1 where B = Zn, Fe, and Al. A turning point was found around x = 0.70 where the Curie temperature ( T C ) of Bi( B)O 3–PZT solid solution increases beyond that of pure PZT. Unlike most PZT-based ceramics, these systems show enhanced tetragonality. This effect is most dramatic in the PZT–5BF system, in which an extremely large c/a ratio of 1.057 is achieved for x = 0.90 sample, leading to the T C as high as 768 K.

Influence of Electromechanical Fields on Dielectric Properties of PLZT−x/65/35 Ceramics (x = 6 and 7)

High density and transparent PLZT−x/65/35 (x = 6 and 7) ceramics with the average grain size of 5–7 μm was obtained by two−stage hot−pressing technology. The measurements of temperature/frequency dependence of the permittivities of these ceramics under uniaxial pressure (0–100 MPa) applied parallel to the ac electric field have been carried out. It was found that uniaxial pressure significantly influences dielectric properties of these ceramics. With the increase of pressure the maximum intensity in ϵ(T) curve decreases, becomes more diffuse and shifts towards higher temperature, dielectric dispersion decreases and classical ferroelectric seems to change to relaxor one. It was concluded, that the applied uniaxial pressure or increasing Ti−ions content in PZT solid solutions induces similar effects. The results were discussed in term of an elastic changes in inter−ionic distances in the crystal structure and domain switching under the action of electromechanical loading.

Dielectric and acoustical high frequency characterisation of PZT thin films

Pb(Zr, Ti)O3 (PZT) is an interesting material for bulk acoustic wave resonator applications due to its high electromechanical coupling constant, which would enable fabrication of large bandwidth frequency filters. The major challenge of the PZT solid solution system is to overcome mechanical losses generally observed in PZT ceramics. To increase the understanding of these losses in textured thin films, thin film bulk acoustic resonators (TFBAR's) based on PZT thin films with compositions either in the tetragonal region or at the morphotropic phase boundary and (111) or {100} textures were fabricated and studied up to 2 GHz. The dielectric and elastic materials coefficients were extracted from impedance measurements at the resonance frequency. The dispersion of the dielectric constant was obtained from impedance measurements up to 2 GHz. The films with varying compositions, textures and deposition methods (sol-gel or sputtering) were compared in terms of dielectric and acoustical properties.

Compatibility of RuO2 electrodes with PZT ceramics

Because of its high electrical conductivity and good diffusion barrier properties ruthenium dioxide (RuO2) is a good electrode material for use with ferroelectric lead zirconate-titanate (PZT) solid solutions. Under certain conditions, RuO2 can react with PZT to form lead ruthenate (Pb2Ru2O6·5) during processing at elevated temperatures resulting in lead depletion from PZT. The standard Gibbs energies of formation of RuO2 and Pb2Ru2O6·5 and activities of components of the PZT solid solution have been determined recently. Using this data along with older thermodynamic information on PbZrO3 and PbTiO3, the stability domain of Pb2Ru2O6·5 is computed as a function of PZT composition, temperature and oxygen partial pressure in the gas phase. The results show PbZrO3-rich compositions are more prone to react with RuO2 at all temperatures. Increasing temperature and decreasing oxygen partial pressure suppress the reaction. Graphically displayed are the reaction zones as a function of oxygen partial pressure and PZT composition at temperatures 973,1173 and 1373 K.

Investigation on La, Ba and PMN Modified PZT Solid Solutions

The influence of multiple doping (A-site modifiers: La, Ba and Pb(Mg 1/3 Nb 2/3 )O 3 ) on dielectric, ferroelectric and piezoelectric properties of Pb(Zr 0.55 Ti 0.45 )O 3 solid solutions synthesized through mixed oxide and columbite precursor methods, respectively were investigated. La and Ba introduction in Pb(Zr 0.55 Ti 0.45 )O 3 resulted in rhombohedral (FE RH ) to tetragonal (FE TET ) phase change whereas PMN and La modified Pb(Zr 0.55 Ti 0.45 )O 3 attained pseudocubic phase with reduced pyrochlore phase. The A-site modification in PZT inhibited the grain growth while density enhanced. The increasing Ba2+ content in PLZT and La 3+ content in PMN-PZT remarkably enhanced ϵ RT and ϵ Tc , respectively. The optimum ferroelectric and piezoelectric properties were observed in 5 mole% Ba doped PLZT and 1.2 mole% La doped 0.3PMN-0.7PZT, respectively.

Preparation of piezoelectric 0.1Pb(Zn 0.5W 0.5)O 3–0.9Pb(Zr 0.5Ti 0.5)O 3 solid solution and thick films for low temperature firing on a Si-substrate

A newly designed lead zirconate titanate (PZT) solid solution 0.1Pb(Zn 0.5W 0.5)O 3–0.9Pb(Zr 0.5Ti 0.5)O 3 was prepared. It is feasible for a low temperature firing. X-ray diffraction shows that its structure is a single perovskite phase, and its thick films were successfully fabricated on a Pt/TiO 2/SiN x /Si-substrate through the screen printing method. A conventional screen printing thick film and a hybrid thick film (screen printing and PZT sol infiltration) was also compared. According to an SEM study, the prepared thick film showed a much denser microstructure with the sol infiltration method. The electrical properties of the prepared PZT solid solution and its thick film were predominantly realized in a low temperature region. The dielectric constant of a conventional screen printing thick film and the hybrid thick film (sintered at 900 °C), was 703.5 and 911.3, respectively.

Dielectric Properties of PbZrO3/PbTiO3 Artificial Superlattices Grown by Pulsed Laser Deposition

PbZrO3 (PZO)/PbTiO3 (PTO) artificial superlattices have been grown on La0.5Sr0.5CoO3 (LSCO) (100)/MgO (100) substrate by pulsed laser deposition with various stacking periods from 1 to 100 unit-cells. The electrical properties of the superlattices were investigated as a function of the stacking period. The dielectric constant and remnant polarization were improved with decreasing the stacking periodicity. The dielectric constant of the superlattice reached 800 at a stacking period of 1unit-cell/1unit-cell (PZO1/PTO1), which is larger than that of the single PZT solid solution film grown at a relative high temperature. Moreover, the remnant polarization reached a maximum, 2Pr = 38.7 μ C/cm2 at 2 unit cell-stacking period. As the total thickness of the superlattices with a 2 unit cell-stacking period (PZO2/PTO2) decreased, the corresponding dielectric constant decreased. As long as the dielectric constant is concerned, the finite size effect was observed in the artificial PZO/PTO superlattice with a thickness down to 20 nm.

New aspects in the (x-P-T) phase diagram of Pb(Zr1-xTix)O3materials (PZT)

PZT solid solutions were studied as a function of pressure and temperature by neutron and x-ray diffraction, Raman spectroscopy and dielectric measurements. Pressure was found to favour low-symmetry structures (Cm, Cc, F1, F1) characterized by a rotation and a reduction of the spontaneous polarisation and by the tilting of (Zr,Ti)O 6 octahedra leading to unit cell doubling (except Cm space group). Additionally, our results show that for Ti-rich PZT. high pressures stabilize the ferroelectric monoclinic phases responsible for the high piezoelectric properties of the MPB composition.

Pressure-induced low symmetry phases in Ti-rich lead zirconate titanate PbZr 0.20Ti 0.80O 3

The titanium-rich PZT solid solution PbZr 0.20Ti 0.80O 3 was studied under high pressure by X-ray diffraction and Raman spectroscopy. A series of low-symmetry phases were observed, including monoclinic (space groups Cm and Cc) and triclinic forms (space groups F1 and F 1 ¯ ) in PbZr 0.20Ti 0.80O 3. High pressure Raman spectra obtained are consistent with a monoclinic ( Cc)–triclinic ( F1) phase transition involving a soft mode at 9 GPa, in agreement with the change in compressibility detected by X-ray diffraction. The strong Raman spectra observed in the paraelectric phase can also be explained by the triclinic F 1 ¯ symmetry.

Dielectric Properties of Na0.5Bi0.5TiO3 – BaTiO3 Ceramics

At the present time, the most widely-used piezoelectric materials belongs mainly to the PZT solid solution system (1-x) PbTixO3 − × ZrTiO3. Because of the possible evaporation of lead oxides during...