Search

This work compares the dielectric properties of two new materials. One was 0.88 bismuth manganite–0.12 lead titanate (noted BM–PT hereafter) ceramics composite obtained by standard high-temperature sintering. The second composite was obtained from powdered ceramics dispersed in epoxy glue (noted BM–PT–epoxy). The occurrence of four phases in the ceramics, using X-ray powder diffraction (XRD), was recognized: orthorhombic Pbam, cubic Pn 3 ‾ m, cubic Pm 3 ‾ m, and monoclinic P2/m phase. Pseudo-Voigt function fitting confirmed significant structural disorder in the BiMn2O5 crystal lattice. Analysis of broadband dielectric spectroscopy data confirmed the applicability of the small polaron model to explain detected relaxation processes. Involvement of oxygen vacancies in relaxation and their correspondence to ordered, uniform potential wells in crystal lattices was deduced. Electric conductivity relaxation times behavior proved the sensitivity of the ceramics’ electrical features to hydrostatic pressure. BM–PT–epoxy composite exhibited dielectric permittivity and losses two orders of magnitude lower than those of BM–PT ceramics that opened new prospects to application. One relaxation process in BM–PT–epoxy composite related to the ceramics fill contribution. Other induced relaxation, observed only in this composite, was attributed to interactions at interfaces between the introduced powdered ceramics and the epoxy glue matrix. We showed that stresses generated either by hydrostatic pressure or through the interfacial interaction of epoxy matrix led to the same results: relaxation times shortening.

Due to requirements for miniaturization and integration of electronic devices, ferroelectric materials with high dielectric permittivity would have potential applications in dielectric capacitors. In this work, (1−x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) powders with x from 0.10 to 0.30 were obtained on the basis of a transitional columbite precursor method, while sintering processes were carried out under three protocols, i.e., (I) 1230 °C for 2 h, (II) 1230 °C for 16 h and (III) 1250 °C for 2 h. The temperature-dependent dielectric properties measured from 25 °C to 225 °C show that, under protocols II and III, the maximum permittivity (em) is significantly improved compared to those obtained via protocol I. A maximum em of 47036 is obtained in x = 0.25 composition under protocol II, and the em is increased by more than 90% at the same composition. In the ceramics sintered through protocols II and III, the characteristics of both dielectric relaxations and dielectric dispersions are also enhanced. In addition, the ferroelectric and piezoelectric properties also show a marked increase in the composition of x = 0.3. Our results suggest that the dielectric and ferroelectric properties of PMN-xPT solid solutions could be effectively enhanced by controlling the sintering protocols.

Lead titanate (PbTiO3) glass and glass ceramics (GCs) are technologically very useful materials that played significant role in various applications due to attractive optical and electrical properties. Based on its structural comparability with the perovskite barium titanate (BaTiO3) lattice, PbTiO3 was the first reported ferroelectric material in 1950. High Curie temperature (490 °C) exhibited by PbTiO3 has led to its utilization for high-temperature applications. The high molecular mass of lead also raises the density of the material, considering its mass of 207.2 g/mol, versus 40.08 g/mol for calcium. Thus, lead-based GCs also have an advantageous use to protect from the highly penetrating X-rays, γ-rays radiations, and high energy storage in barrier layer capacitors. Dielectric behavior of the GCs mainly depends on its doping with numerous oxides such as La2O3, Bi2O3, CrO3, Nb2O5, the heat treatment processes, and their respective soaking times. Herein, we report the different methods of the synthesis of PbTiO3 glass and GCs which showed distinct optical, structural, dielectric, and mechanical properties. Moreover, this review emphases on the past and recent dielectric characteristics of the various PbTiO3 glass ceramics.

The influence of La3+-doping on the electrocaloric effect (ECE) of the 0.75(Pb1-3x/2Lax)(Mg1/3Nb2/3)O3-0.25(Pb1-3x/2Lax)TiO3 (L-PMN-PT: x/75/25 x = 0.0–4.0 mol.%) ceramics was studied. With the increase of La3+-doping in these ceramics, the relaxor ferroelectric properties increase, while the average grain size, coercive field E c and Curie temperature T C decrease. As a result, a maximum adiabatic temperature change Δ T as high as 0.68 K, measured by direct measurement method, was achieved under a lower electric field ( E ) intensity of 5 kV/mm at 383 K for samples with x = 2.0 mol.%. Besides the high Δ T value, the La3+-doping also leads to a temperature insensitivity of ΔT. The variation of Δ T is less than 0.15 K, or 28.3%, over a wide temperature range of 303–423 K. The La3+-doped PMN-PT ceramics, with large and temperature insensitive Δ T over a broad temperature range, is very helpful for practical application. The reduction of E c and T C can be attributed to the suppression of long-range coupling between oxygen octahedrons due to the partial replacement of Pb2+ by La3+. The temperature insensitivity of ECE is attributed to the enhancement of relaxor ferroelectric properties.

This novel research work addresses the physical properties of Lead titanate (PT), PbTiO3 sample with additives. The modification of this sample was carried out by adding calcium in proportion of 5 to 15mol%. The samples in bulk form were synthesized by utilizing traditional method of solid state synthesis. The properties like structural analysis, and grain size determination were studied for the PbTiO3 sample & for the calcium modified lead titanate (PCT). The phase identification, structural characterizations and microstructural analysis hasanalyzed in this manuscript.

Substitution of alkali earth metal ion of Sr2+, in the Pb2+ site of Pb(Mg1/3Nb2/3)O3–PbTiO3 is expected to induce functional modulations in the system. Doping of 4 at.% of Sr2+ in 0.68PMN-0.32PT was carried out to lower the transition temperature, and to investigate the intended ferroelectric and dielectric variations. Excellent relaxor property was observed in the doped sample without appreciable reduction in remnant polarization. Doping with Sr2+ led to a reduction in transition temperature from 165 °C to 117 °C. Doped sample exhibited remnant polarization Pr = 16.2 μC/cm2, Squareness factor (Rsq) = 1.05 and Relaxor exponent (γ) around 2. Modulation in the functional response was exhibited by the doped composition, having low transition temperature, and its prospect in electrocaloric applications was analyzed.

Glasses were prepared using the conventional melt quench technique and converted to glass-ceramics by two stage heat treatment. The density of glass and glass–ceramic samples was measured by Archimedes principle. Formation of ferroelectric phase in the glass–ceramic samples was confirmed using XRD. The resulting glass-ceramics contained most stable tetragonal lead titanate (PbTiO3) phase along with lead zirconate titanate phase. Volume fraction of tetragonal lead titanate phase was calculated from XRD. Microstructure of the glass-ceramics revealed the formation of lead titanate crystals. Dielectric properties were studied at different frequencies and temperature. Ferroelectric hysteresis measurement was carried out using PE-loop tracer. The presence of dielectric and ferroelectric properties in these samples may further explored for piezoelectric applications.

The frequency and temperature depending structural, morphological and dielectric features of the Neodymium (Nd+3) doped bismuth ferrite (BFO; BiFeO3) and lead titanate (PT; PbTiO3) electronic system have been processed by using solid state chemical route. The capacitive properties of the prepared solid ceramic [(Pb0.9Bi.05Nd0.05)(Fe0.1Ti0.9)O3] have been investigated experimentally. The apprehension of the preferred sample material shows tetragonal crystal structure which is affirm through XRD (X-ray diffraction) investigation. The uniform grain scattering is perceived from the SEM study. The rare earth Nd modified BFO-PT compound unveils high dielectric constant and low tangent loss with respect to temperature and frequency, which substantiate the material as a promising candidate for invention of electronic devices.

A novel lead zinc titanate tungsten oxide (PbZn[Formula: see text]Ti[Formula: see text]W[Formula: see text]O[Formula: see text] single perovskite was synthesized employing a cost-effective solid-state reaction technique. A phase transition occurs from tetragonal (P4mm) to monoclinic (C2/m) after substituting zinc (Zn) and tungsten (W) into the B-site of the pure lead titanate. The average crystallite size and micro-lattice strain are 66.2[Formula: see text]nm and 0.159%, respectively, calculated by the Williamson–Hall method. The grains are uniformly distributed through well-defined grain boundaries and the average grain size is about 17.8[Formula: see text][Formula: see text]m analyzed from the SEM micrograph. Raman spectrum suggests the presence of all constituent elements in the sample. The UV–Visible study suggests that the sample is suitable for photovoltaic applications because of high bandgap energy [Formula: see text][Formula: see text]eV. The dielectric study confirms the negative temperature coefficient resistance (NTCR) behavior of the sample. The activation energy increases from 13.9[Formula: see text]meV to 142[Formula: see text]meV with a rise of temperature suggesting that ac conductivity is thermally activated. The thermally activated relaxation process was managed by immobile charge carriers at low temperatures while defects and oxygen vacancies at higher temperatures. The presence of the asymmetrical curves in modulus plots confirms the non-Debye-type behavior. Both Nyquist and Cole–Cole semi-circular arcs confirm the semiconductor nature of the sample.

Technology is suggested for fabrication of ceramic piezoelectric materials from the lead-containing ferroelectric phase. The technology includes a low-temperature synthesis of ultradispersed lead titanate and zirconate powders and also of phases of solid solutions on their basis and the low-temperature procedure for sintering of ceramic fabricated from ultradispersed powders of ferroelectric phases. As precursors used in the suggested low-temperature synthesis serve lead glycerate and tartrate. It was found that, when interacting (at temperatures of 240–330°C) with hydroxo-peroxo-aqua complexes of titanium and(or) zirconium(IV) in the course of 30–40 min, the precursors form ultradispersed powders of these phases, which are single-phase and contain particles with average size of less than 100 nm. It was shown that using the suggested technology makes it possible not only to reduce the energy expenditure for separate procedures for synthesis of ultradispersed ferroelectric phases and for synthesis of piezoelectric materials, but also to substantially diminish the discharge of lead(II) compounds into the atmosphere of industrial premises. It was also shown that the technology enables fabrication of piezoelectric materials with prescribed values of electrical parameters.

A systematic investigation of the seeding effects on the mechanochemical synthesis of lead magnesium niobate – lead titanate 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 (PMN–10PT), one of the most studied relaxor-ferroelectric material for electrocaloric applications, is reported. The perovskite crystallisation process was followed by X-ray diffraction using the Rietveld refinement method and transmission electron microscopy. Compared to the mixed-oxides case which requires 143 h of high-energy milling, the milling time needed to obtain a phase-pure PMN–10PT perovskite using PT seeds is reduced almost twice. The presence of PT seeds leads to faster transitions from the amorphous to pyrochlore and to perovskite phases compared to the mixed-oxides case. A sintering study demonstrates, for the first time, that a second, metastable, pyrochlore phase is taking part in the processes of perovskite formation. The PMN–10PT ceramic prepared from the PT-seeded powder exhibits electrocaloric properties comparable to reported values for PMN–10 PT prepared from oxides.

Various composition of lead bismuth titanate borosilicate glasses doped with one mol percent of cerium oxide in the system 55[(PbxBi1−x)TiO3]-44[2SiO2.B2O3]-1CeO2 (0.0 ≤ x ≤ 1.0) were prepared using rapid melt quenching technique. X-ray diffraction study confirmed the amorphous nature of the samples. Structural and optical properties of the glass samples were carried out using infrared spectroscopy, Raman spectroscopy, and UV–vis spectroscopy respectively. Absorption peaks in IR spectra mainly occurred due to asymmetric vibrational stretching modes of the B O bond of trigonal BO3 units. Raman study revealed that the structural network of B-O-B stretching in metaborate rings of the glass sample. The optical band gap values were determined from Davis and Mott plots. On the basis of the differential thermal analysis, all glass samples were crystallized by given a controlled heat treatment schedule within the temperature range 607–693 °C. For the determination of phase, crystal structure and crystallite size, XRD was also performed on the glass ceramic samples. To understand the surface morphology of the glass ceramic samples, scanning electron microscopy was employed. The dielectric properties were studied with varying temperature at few selected frequencies. The maximum value of relative dielectric constant, er was found to be 973 at 100 Hz with dissipation factor, D, 3.99 for bismuth free lead titanate glass ceramic sample (x = 1.0).

PbTiO3 (PTO) suffers from difficulty in preparing high-density robust bulk ceramics, which in turn has been a bottleneck in thin films growth with physical vapor deposition (PVD) methods. In the present work, we prepared non-doped PTO thin films by a pulsed laser deposition (PLD) method with either a single PTO target or a mosaic target consisting of PbO and TiO2 pie-shaped pieces. On the PTO single target, laser irradiation caused selective ablation of Pb, resulting in Tirich cone-shaped pillar structure on the surface, whereas the irradiated surface of PbO and TiO2 pieces was smoother. Epitaxial PTO films deposited on SrTiO3 (001) substrates from the pie-chart targets with PbO:TiO2 areal ratio from 3:5 to 5:3 resulted in composition, crystallinity, flatness, and ferroelectric properties almost independent of the areal ratio. The averaged composition of each film was close to stoichiometric, suggesting a compositional self-control mechanism. For growing epitaxial and high-quality non-doped PTO films, a PbO-TiO2 pie-chart target is advantageous in easiness of handling and stable surface structure., This research was supported by Spanish Ministry of Competitiveness (projects MAT2016-77100-C2-1-P and PID2019-108573GB-C21) and the AGAUR agency (project 2017SGR). ICN2 is funded by the CERCA programme/Generalitat de Catalunya and by the Severo Ochoa programme of the Spanish Ministry of Economy, Industry and Competitiveness (MINECO, Grant No. SEV-2017-0706).

Glass samples with composition (35- X) B2O3 − (40 +X) PbO - 25 TiO2 (where X = 0, 2.5, 5, 7.5 and 10 mol %) were prepared using conventional quenching technique. These glass samples were converted to glass ceramics by following two stage heat treatment schedules. The density (ρ) values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and Coefficient of Thermal Expansion (CTE) results of the glass–ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate (PbTiO3) as a major crystalline phase and lead borate (PbB2O4) as minor crystalline phase. The microstructure of glass ceramic samples contains nano crystallites of lead titanate embedded in a borate glass matrix.

The composition of Anthracene and Lead Titanate is prepared using Solid State reaction method. Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Lead (II) titanate is an inorganic compound with the chemical formula PbTiO3. It is the lead salt of titanic acid. Lead (II) Titanate is a yellow powder that is insoluble in water. At high temperatures, lead Titanate adopts a cubic perovskite structure. The samples of Anthracene Lead Titanate composites of suitable mixture ratio are prepared using Solid state reaction method. The Crystal structure of the calcined powders and also sintered ceramics were analyzed using XRD (X-ray diffraction). The microstructure of the sintered ceramics has been investigated by using SEM (Scanning Electron Microscopy).The dielectric constants were calculated for different mixture ratios and at different temperatures are reported in this paper. It was observed that an increase in temperature there is a change in the dielectric constants has also been reported in this paper. It observed that the dielectric constant increasing with temperature increases.

In the present study we have made an attempt to make and use a milling map in the mechanochemical synthesis of nanocrystalline lead titanate (PT) ceramics. In order to do this, lead titanate was synthesized by mechanical alloying from a powder mixture of PbO and TiO2. By varying the milling parameters such as milling speed and ball to powder ratio over a wide range, a series of milling energies were obtained.

Tetragonal lead titanate ceramics in nano particles forms were fabricated via sol-gel method. The gelation was achieved via mixing a solution of lead acetate, titanium isopropoxide in a solvent system of ethanol and acetylacetone. The gel was heated in a normal air oven at 120°C for 5 hours to get ceramic powder which was calcined at 600°C for two hours and cintered upto 1100°C. The calcined powder was characterized by X-ray diffraction XRD and SEM analysis. It has been observed that the particle size increases with temperature with a decrease in grain boundary area.

Lead titanate (PbTiO3) ceramic was produced by solid state reaction via a vibratory ball milling machine and subsequent heat treatment. The effect of milling time on the particle and crystallite size of PbTiO3 powder was investigated. Powder samples were studied using particle size analyser (PSA). The annealing process was up to 1,000°C and the products were examined by X-ray diffractometer (XRD) to determine phase formation and crystallite size. It was found that the average particle size of powder initially increased due to laminated layers formation and then decreased to an asymptotic value of ~0.8 μm as the milling time extended even to a relatively longer time. Single-phase PbTiO3 were achieved at 600°C for 1 h holding time of annealing temperature. Annealing the sample of the particles at 1,000°C resulted in a dense compact and promoted the formation of particles containing nanocrystallites. The crystallite size of PbTiO3 increased as the function of temperature of annealing process.

Temperature dependent magnetoelectric studies are performed for 0.37 BiScO3-0.63 PbTiO3-NiFe2O4 laminate composites in the temperature range of 25 °C–200 °C. The co-fired laminates are sintered at two different temperatures, 1100 °C and 1200 °C, closer to the sintering temperature of the ferroelectric and ferrite phases. The effect of sintering temperature on co-fired laminates is investigated by analyzing the structural, morphology, ferroelectric properties along with the direct and converse magnetoelectric coefficients. With increase in sintering temperature, the magnetoelectric coupling coefficient of the co-fired laminate is found to increase. The direct magnetoelectric coefficient of co-fired laminate, sintered at 1200 °C, is found to be comparable to that of the epoxy bonded laminate. Finally, the temperature dependent direct magnetoelectric studies are carried out in co-fired laminates and the results are compared with that of epoxy bonded laminate. The magnetoelectric interaction in epoxy bonded laminate, strongly affected by temperature, can be ascribed to softening of the epoxy layer. The co-fired laminate, which has no epoxy layer, exhibits a better thermal stability in terms of stable magnetoelectric coefficient up to 200 °C making it a suitable candidate for high temperature magnetic field sensors.

Of all the piezoelectric ceramics, lead titanate (PbTiO3) has an important place as an electromechanical transducer. In the present article PbTiO3 synthesized by sol–gel technique and microwave processed is presented. The sintered PbTiO3 is found to be of high density. The sintered PbTiO3 crystal structure and crystallinity confirmed by powder X-ray diffraction and sample weight loss and decomposition investigated by thermal analysis. Prepared PbTiO3 functional groups confirmed by FT-IR spectrum and phase formation analyzed by Raman spectra. Sample spherical morphology confirmed by high-resolution scanning electron microscopy (HRSEM) and transmission electron microscopy (TEM). The particle size found to be 77 nm from TEM. The variation of dielectric constant and ac conductivity with temperature and frequency of PbTiO3 are investigated. The value of σdc is found to be 1.767 × 10−2 S/cm at transition temperature using the Nyquist plot. The ferroelectric hysteresis loop and piezoelectric coefficient d33 confirm the ferroelectric and piezoelectric nature of the PbTiO3 (PT).

Lead zinc niobate (PZN) and lead titanate (PT) solid solutions close to the morphotropic phase boundary (MPB) exhibit unusually large dielectric and piezoelectric constants. PZN-PT ceramics with a composition close to the MPB processed by the conventional route yield ceramics with a pyrochlore structure. In the last few decades, attempts to synthesize PZN-PT powders with perovskite structure via traditional ceramic methods and novel chemical processing routes have failed. In the present research, an analysis was made of the effect of the calcination atmosphere on the formation of perovskite phase in PZN-10PT powders. To this end, thermal analyses were carried out in four different atmospheres: oxygen, air, argon and nitrogen. The powders were calcined at the temperatures at which the DTA curves presented peaks, and the resulting phases were identified by X-ray diffraction.

A functional ceramic based on the lead titanates is synthesized and its radiation-protective characteristics are studied. The phase compositions of lead titanates synthesized with the use of different proportions for the initial components are compared and the component ratio is optimized to ensure that the resulting titanates of heavy metals have an acceptable phase composition. The absorption of gamma radiation by synthesized lead titanate is studied and this product is compared to traditional protective materials. It is shown that in terms of its protective characteristics lead titanate is surpassed only by pure lead and barite concrete.

In this paper we report, the magnetic, dielectric and ferroelectric properties 0.9Pb (Zr0.47Ti0.53) O-3-0.07Pb(Mn1/3Nb2/3)O-3 0.03Pb(Ni0.5W0.5)O-3 ceramic, which is synthesized by conventional solid state reaction method. X-ray diffraction technique reveals the formation of pure perovskite phase with tetragonal structure. The remnant polarization (P-r) and spontaneous polarization (P-s) of sample were observed similar to 9.57 mu C/cm(2) and similar to 15.09 mu C/cm(2), respectively, at an applied electric field of 47 kV/cm. The dielectric permittivity at room temperature (epsilon' RT) was found similar to 933 at frequency of 100 Hz. The maximum magnetic moment was observed similar to 7.7x10(-3) (emu/g) at applied magnetic field of 20 kOe. In addition, strain versus electric field (S-E) behavior shows a strain of similar to 3.5% at an applied electric field of 47 kV/cm. The observation of magnetic as well as ferroelectric properties at room temperature reveals that our multiferroic system may be useful for device applications. (C) 2017 Elsevier Ltd. All rights reserved.

Lead titanate is one of the important member of perovskite materials group having ABO 3 type structure. It exhibits piezoelectric as well as pyroelectric properties. It also shows high ferroelectric property. Ca modified lead titanate having stoichemetric formula Pb 1-x Ca X TiO 3 was synthesized by High Energy Ball Milling (HEBM) method at room temperature. Dopant calcium was incorporated in 1 2 and 3 weight percent simultaneously. Structural and electrical properties were studied by taking measurement with standard instruments; results were compared with pure one. Impedance and quality factor analysis of ca modified lead titanate ceramics were done.

Perovskite type (Pb1-1.5x Lax0.5x)TiO3 (PLT) ceramics with x = 0.21, 0.22, 0.23, 0.24, 0.25 were prepared by the sol-gel method. Their structural, optical, and dielectric properties were investigated. The crystallite compounds were obtained by calcinating the mixture of PbCO3, TiO2, and La2O3 at 1000ºC for different time periods. After 4 h annealing, PLT23 sample, no secondary phases have been observed in the XRD spectrum of the PLT sample with 23% La content (PLT23). This sample appears to be notably distinguished in its structural, optical, and dielectric characteristics compared with other samples.

Combined experimental and theoretical approach to investigate the structural and electronic properties to Sr-doping lead titanate (PT:Sr) was carry out. It is well-known at room temperature PT crystallizes in tetragonal distorted perovskite structure with space group symmetry P4mm. At higher temperature (T > 490 °C), this compound presents a tetragonal-cubic phase transition and, due to its high tetragonality (c/a), the PT ceramics can develop cracks during the cooling process. The Sr-doping reduce this lattice anisotropy, and the doped ceramics become denser than the pure ones.The ceramic materials lead titanate (PT), lead strontium titanate (PST) and strontium titanate (ST) were synthetized by Polymeric Precursor Method. The crystal structure systems are taken from Rietveld refinement. These materials were characterized by theoretical X-ray diffraction data, total state densities (DOS), Gap values and charge maps. The gap values obtained were 3.60 eV, 3.20 eV and 3.70 eV for PT, PST and ST, respectively. The c/a ratio was investigated with different strontium concentration in the PT structure, showing that the tetragonality decreased from tetragonal to pseudo-cubic. Therefore, decreases tetragonality (c/a) and improves the physicochemical properties of the material. The presence of the atom in the PT matrix promotes an electronic stability in the strucutre of the PST inducing an improvement in the proportions of the material. In addition, ferroelectric properties can be adjusted by altering the Pb/Sr molar ratio. This behavior was associated to a lattice contraction effect caused by the diferent ionic radii between Pb and Sr. In this context, the present study characterizes the effects of Sr-doping upon structural and electronic properties of lead titanate matrix (PT). A periodic quantum-mechanical method based on DFT theory at B3LYP level has been used. These theoretical results are in agreement with the experimental. DOI: http://dx.doi.org/10.17807/orbital.v11i2.1342

Lead titanate (PT) and lead zirconate (PZ) have been prepared due to mixed oxide (solid state reaction) at sintering temperature 900°c of PT and 1100°c of (PZ) in air for 3 hours. Structure and the theoretical density of the piezoelectric ceramic samples of materials (PT) and (PZ) has been confirmed by X-ray powder diffraction studies. The crystalline size and strain are measured from X-ray peak brocading analysis by using Williamson-Hall plot and Debye-Sharers formula. The physical density of the samples sintered are measured using the Archimedes method. Our results indicate that dielectric constant measurements decreases with increases of frequencies.

Glass samples with composition (35-X) B2O3 − (40 +X) PbO - 25 TiO2 (where X= 0, 2.5,5, 7.5 and 10 mol %) were prepared using conventional quenching technique. It was observed that as PbO content increases the values glass transition temperature (Tg) and crystallization temperature (Tc) decreases. The replacement of boron by a bigger Pb ion expands the network there by reducing the glass transition temperature (Tg). These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The density(ρ) values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and Coefficient of Thermal Expansion (CTE) results of the glass–ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate (PbTiO3) as a major crystalline phase and lead borate (PbB2O4) as minor crystalline phase. The microstructure of glass ceramic samples contains nano crystallites of lead titanate embedded in a borate glass matrix. As the content of glass former (B2O3) is reduced, the PbTiO3 crystals precipitated in glass matrix are observed to increase. The dielectric constant values of glass ceramic samples are higher than those of corresponding glass samples.Glass samples with composition (35-X) B2O3 − (40 +X) PbO - 25 TiO2 (where X= 0, 2.5,5, 7.5 and 10 mol %) were prepared using conventional quenching technique. It was observed that as PbO content increases the values glass transition temperature (Tg) and crystallization temperature (Tc) decreases. The replacement of boron by a bigger Pb ion expands the network there by reducing the glass transition temperature (Tg). These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The density(ρ) values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and Coefficient of Thermal Expansion (CTE) results of the glass–ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate (PbTiO3) as a major crystalline phase and lead borate (PbB2O4) as minor crystalline phase. The microstructure of glass ceramic samples contains nano crystallites of lea...

Perovskite lead titanate PbTiO3 (PT) powder and ceramics were synthesized using solid state reaction technique. The PT single phase powder was detected by X-ray diffraction where the phase obtained by sintering at 700 °C for 2 h. Morphology of the ceramics powder were studied using SEM–EDS. It was found that the particle size tend to increase with increasing sintering temperature. Hot stage microscope has been used to investigate the sintering curve of the calcined powder. The pure calcined powder was prepared as humidity sensors by the screen-printing technique. Thereafter, DC resistance measurements were performed in the presence of relative humidity at room temperature where the powder shows a poor sensitivity towards relative humidity. The phase transition from ferroelectric to paraelectric was identified by differential thermal analysis, and was detected at 493 °C. The difference between using alumina and platinum crucibles during processing has been discussed.

Conventionally, effective mechanical vibration energy harvesting is based on (Pb,Zr)TiO3 (PZT) ceramics, poly(vinylidene fluoride) (PVDF) polymers or PVDF/PZT or other piezoelectric composite materials, and their working temperature is normally limited to room temperature (R-T) or below 150 °C. Here, bismuth scandium lead titanate (BiScO3-PbTiO3, abbreviated as BSPT) ceramic is reported which has a high Curie temperature point around 450 °C and its application for high-temperature (H-T) vibration energy harvesting. Experimental results show that it exhibits an excellent H-T piezoelectricity, converting mechanical vibration energy into electric power effectively in a wide temperature range from R-T till 250 °C. This research shows the BSPT piezoelectric energy harvester having the potential application for self-power source of wireless sensor network system in high temperature circumstance.

A series of La doped lead titanate samples, with composition Pb1−xLaxTi1−x/4O3 (PLTx), where x=0.00; 0.02; 0.04; 0.06; 0.07; 0.08; 0.10; 0.12; 0.14; 0.16; 0.18; 0.21 and 0.22 was prepared using the sol–gel process. Addition of La gives rise to the two well-known phenomena: diffuseness and relaxation around the ferro-to-paraelectric transition; the two parameters related to these phenomena, and which give a satisfactory interpretation of them, have been estimated using the Uchino's quadratic law. This diffuse phase transition (DPT) has been investigated with the help of the Landau–Devonshire cluster theory and the model of Cheng et al., to show that polar regions may be generated around the DPT and far from the temperature, Tm, of the maximum of the dielectric permittivity, which have as a direct consequence a non vanishing polarization even if T>Tm.

Barium lead titanate ferroelectric ceramic is a promising material for electronic devices at high frequency and high temperatures. These fine-grained ceramics were obtained at a low sintering temperature of 900°C within a short sintering time by means of a new sintering method – spark plasma sintering (SPS). The ceramics are highly densified to >99% of the theoretical X-ray density with homogeneous microstructures, signifying that the SPS process is effective for the densifying of compacts and the inhibition of exaggerated grain growth. Temperature dependence of dielectric constant of SPS pellets shows three times higher than the conventional sintering (CS) Ba0.8Pb0.2TiO3 (BPT) pellet. The variations in properties between SPS and CS materials are mainly because of the differences of the resultant microstructures, especially grain size, of the ceramics.

In this work, the ferroelectric domain structure of (Pb0.79La0.21)TiO3 transparent ceramics and its response to an applied electric field were investigated by piezoresponse force microscopy (PFM). A qualitative three-dimensional reconstruction of the domains by PFM measurements revealed that the domain structure consists in stripes in two size scales (micro and nanometer) separated by 90° domain walls coexisting with 180° domains. While the nanoscale 90° domains were found arranged in organized structures, (e.g., lamellas, herringbones, and other unusual configurations), the 180° domains form a “labyrinth” structure, typical of ferroelectrics with a degree of disorder. Local application of an electric field reveals different coercive voltages to reorient 180° and the two types of 90° domains and the appearance of a different nanoscale 90° domain structure after poling. While the labyrinth structure is destroyed with relative low voltages, the created 90° domains structure persists, avoiding the formation of a single-domain structure.

In this paper, we have reported a conformable PbTiO3 ceramics doped with Ni by standard double sintering technique as well as chemical co-precipitation method which were successfully synthesized by means of carefully controlled processing parameters. Single phase formation was confirmed through X-Ray Diffraction (XRD) analysis, IR spectroscopy, SEM micrograph and TEM images. Discussion and comparison between both preparation methods were made on the basis of observed results. The tetragonality c/a decreased from 1.049 to 1.0276 for ceramic samples and decreased from 1.06519 to 1.0365 for co-precipitation samples by increasing Ni content. TEM images show small ferroelectric domains of about 3 to 14 nm for the co-precipitation sample and 26 to 48 nm for the ceramic samples. The SEM of co- precipitation samples shows that the microstructure is very dense. The behavior of e identifies that our samples are nonrelaxor. Increasing the Ni concentration increases the value of dielectric constant and the Tc is shifted to lower temperature.

This article demonstrates that both ferroelectric and magneto-electric responses can be attained simultaneously in the ceramics of NiTiO3, Bi-modified NiTiO3, Bi- and PbTiO3 -modified NiTiO3 synthesized by the precursor solution method. The samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV–Vis) spectroscopy, electric field dependent polarisation (P-E hysteresis measurement), magneto-electric coefficient measurement, impedance spectroscopy, and electronic conductivity measurement techniques in different experimental conditions. The modifications of NiTiO3 with bismuth and then with lead titanate (PbTiO3) have provided a pure-phase perovskite structure with an excellent crystalline morphology, featuring a high relative permittivity and enhanced ferroelectricity and magneto-electric effect. It also exhibits that not only the magneto-electric effect is enhanced, but also the leakage current is reduced with the modifications.

Some yttrium modified BiFeO3–PbTiO3 (BYFO-PT) compounds have been fabricated using a standard ceramic technology (solid-state route). The structural analysis from X-ray diffraction (XRD) data ensures the formation of the rhombohedral phase of the compounds. The prepared materials have major bismuth ferrite (70%) and lead titanate (30%) with few impurity phases. The materials are found to have a high dielectric constant and low tangent loss. The relaxation mechanism is identified from the peaks appearing in impedance and modulus curves. The materials show a negative temperature coefficient of resistance (NTCR) semiconductor type behavior in the temperature range of 250 °C–400 °C. In addition, grain and grain boundary effects are observed through the Nyquist plots. The activation energy (Ea) of the compounds is calculated from the slope of inverse temperature versus AC conductivity at the high-temperature range. The ferroelectric nature of the compounds is confirmed by electric field dependent polarization (PE-hysteresis) loops.

The pyrochlore phase in ferroelectric and piezoelectric materials is the main obstacle device application due to its poor electrical properties. Especially, the pyrochlore phase is frequently observed in the perovskite-based metal-oxide materials including piezoelectric and ferroelectric ceramics, which are based on solid-state reaction methods for fabrication. To overcome these problems, advanced innovative methods such as partial oxalate process will be investigated. In this method, crystalized magnesium niobite (MN) and lead titanate (PT) powders will be coated with a certain amount of lead oxalate and, then, the calcination process can be carried out to form the PMN-PT without pyrochlore phase. In this study, (1&minus, x)PMN-xPT ceramics near the morphotropic phase boundary (MPB), with compositions of x = 0.25&ndash, 0.40, have been prepared employing the partial oxalate method at various temperatures. The crystalline, microstructure, and piezoelectric properties of (1&minus, x)PMN-xPT ceramics depending on the sintering temperature were intensively investigated and discussed. By optimizing the sintering temperature and compositions from the PMN-PT ceramics, the maximum value of the piezoelectric charge coefficient (d33) of 665pC/N, planar electromechanical coupling factor (kp) of 77.8%, dielectric constant (&epsilon, r) of 3230, and remanent polarization (Pr) of 31.67 &mu, C/cm2 were obtained.

The unique properties and great variety of relaxer ferroelectrics make them highly attractive in energy-storage and solid-state refrigeration technologies. In this work, lanthanum modified lead titanate ceramics are prepared and studied. The giant electrocaloric effect in lanthanum modified lead titanate ceramics is revealed for the first time. Large refrigeration efficiency (27.4) and high adiabatic temperature change (1.67 K) are achieved by indirect analysis. Direct measurements of electrocaloric effect show that reversible adiabatic temperature change is also about 1.67 K, which exceeds many electrocaloric effect values in current direct measured electrocaloric studies. Both theoretical calculated and direct measured electrocaloric effects are in good agreements in high temperatures. Temperature and electric field related energy storage properties are also analyzed, maximum energy-storage density and energy-storage efficiency are about 0.31 J/cm3 and 91.2%, respectively.

Glass samples with composition (50 - X) PbO - (25 + X) TiO2 - 25 B2O3 (where X = 0, 5, 10 and 12.5 mol %) were prepared using conventional quenching technique. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate as a major crystalline phase. The SEM results show rounded crystallite of lead titanate. The ferroelectric nature of all the glass ceramic samples is confirmed by P - E hysteresis measurements. The extended heat treatment of glass ceramic samples at 593K for 10 h exhibited saturated hysteresis loops with higher values of remnant polarization.

The intensities of the Raman lines of the ceramic complex (lead titanate) have been investigated as a function of the relation of the areas of the low Raman frequency modes E(1TO) and silent. A change of tetragonal phase into cubic material was observed by Raman spectrjky. The samples were subjected to the same conditions at the time of making the Raman measurements. The UV-vis spectra of absorption suggested a change in energy levels with increasing concentration of lanthanum element (La). This study’s intention is to observe structural changes in the material by means of Raman intensities without using the traditional central position of the peak width in the bands. Resumen Las intensidades de las líneas Raman del cerámico complejo (titanato de plomo) se han investigado como una función de la relación de las áreas de los modos Raman de baja frecuencia E(1TO) y silenciosos. Un cambio de fase tetragonal dentro del material cúbico fue observado por espectroscopía Raman. Las muestras fueron sometidas a las mismas condiciones en el momento de realizar las mediciones de Raman. Los espectros UV-vis de absorción sugirieron un cambio en los niveles de energía al aumentar la concentración del elemento de lantano (La). La intención de este estudio es observar cambios estructurales en el material mediante intensidades Raman sin utilizar la posición central tradicional del ancho máximo en las bandas.

Relaxor ferroelectrics Pb(Mg 1/3 Nb 2/3 )O 3 –PbTiO 3 (PMN–PT) have attracted considerable attention because of their excellent electrical properties, which include high dielectricity and piezoelectricity. Their thin films are promising for use as super capacitors and piezoelectric actuators. However, the reported electrical properties of PMN–PT thin films, such as dielectric and piezoelectric properties, are markedly lower than those of bulk ceramics and single-crystals. This study investigated the effects of synthesis conditions such as annealing temperatures, excess lead amounts, and the molecular design of the precursor solution on the electrical properties of the Chemical Solution Deposition (CSD)-derived PMN–PT thin films to deposit single-phase perovskite PMN–PT thin films with superior electrical properties on a Si substrate at lower temperatures. Results of studies demonstrated effectively that suitable processing is necessary to elicit the enhanced electrical properties of PMN–PT thin films, such as introduction of suitable seeding layers and optimization of synthesis conditions. Results show that CSD-derived polycrystalline 0.65PMN–0.35PT thin films with preferred orientation exhibited a higher dielectric constant over 4000 (1 kHz, at room temperature) and higher remanent polarization of P r = 27.7 μC/cm 2 (1000 kV/cm, at room temperature) as well as a higher electrostrictive constant of d 33 about 200 pm/V. Further investigation and development are expected to improve these electrical properties of the PMN–PT thin films by stress engineering or residual stress.

The most important thing in preparing thin films ceramic material such lead titanate, PbTiO3 is the behavioral of microstructural changes due to the applying heat treatment during crystallization process. In general, the imperfection of PbTiO3 surface morphology such as porosity, grain boundaries, existence of microcrack films, films out-diffusion and others are caused by this factor, heat transfer element and found very interesting to be discussed towards next electrical characterization. However, the present study only focuses on the surface morphology of PbTiO3 thin films that observed by both field emissions scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The details of measurement for observation will be explained later. The preparation of PbTiO3 thin films were done trough simple sol-gel spin coating method deposited on ITO coated glass substrate.

The electrical properties of stoichiometric and nonstoichiometric samples of barium lead titanate ferroelectric ceramics with the initial composition Ba0.95Pb0.05TiO3 have been studied by impedance spectroscopy in weak electric fields at temperatures from 295 to 620 K and frequencies from 0.3 to 103 kHz. In addition, the optical properties of the samples have been investigated in the infrared spectral region at room temperature. The measurements were made before and after vacuum quenching, which helped to produce nonequilibrium point defects: oxygen vacancies.

High temperature ferroelectrics for thermally stable devices that can detect pressure and temperature are of great industrial interest. Here we describe composites of lead titanate (PT) particle-polyetherimide (PEI) polymers with stable dielectric and piezoelectric properties over a broad range of temperature and frequency. The reported materials have a low dielectric loss (tan delta similar to 0.001 at 1 kHz) and a high piezoelectric voltage coefficient of 100 mV m N-1 at record temperatures of 175 degrees C. We demonstrate that a small ceramic loading leads to a significant change in thermally stable piezoelectric behavior, while the processability as well as mechanical properties remain comparable to those of the neat polymer. Careful design of the microstructure is performed by dielectrophoretic assembly of ferroelectric PT micro-particles to induce micro- wire configurations, which is shown to be a key element in attaining high functionality at low ceramic loading. Thermal imidization of the composites is performed in two steps, first partial imidization at 60 degrees C to form free standing films containing polyamic acid, followed by full imidization at 200 degrees C and 300 degrees C. The presence of highly polar polyamic acid results in higher dielectric permittivity and electrical conductivity that facilitate efficient poling. Upon complete imidization of the films at 300 degrees C the dielectric and piezoelectric properties are tested at elevated temperatures. A fully imidized composite contains completely closed imide groups, resulting in a thermally stable material with a very low dielectric loss that maintains more than 85% of its room temperature piezoelectric sensitivity up to 175 degrees C. The room temperature piezoelectric voltage coefficient shows more than 400% improvement over that of PT ceramics. Materials innovation institute M2i [M62.3.11438] This research was carried out under project number M62.3.11438 in the framework of the Research Program of the Materials innovation institute M2i (www.m2i.nl).

Glass samples with composition (50 - X) PbO - XCaO - 25 TiO2 - 25 B2O3 (where = 0, .5, 10 and 15 mol %) were prepared using conventional quenching technique. It was observed that with the addition of alkaline earth oxides to lead borate glass containing TiO2 alters the network (conversion of BO3 to BO4) increasing the rigidity of the glass which enhances the Tg. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The density values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and CTE results of the glass–ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate as a major crystalline phase and Ca3Ti2O7 as minor crystalline phase. The ferroelectric nature of all the glass ceramic samples is confirmed by P - E hysteresis measurements.

Effects of Ni, Nb and Mn co-doping on microstructural, dielectric and electromechanical properties of lead titanate (PT) dense ceramics, obtained as a result of decreasing lattice anisotropy with increasing amount of co-dopants, were investigated. Different values of the average valence (AV) of Ni–Nb co-dopants were obtained by mutual valence compensation between these acceptor–donor ions of various relative concentrations. Significantly higher amounts of Mn 2+ (resulted by reduction of Mn 4+ in presence of donor co-dopants) were found in materials with Ni–Nb AV > 4+. These materials show higher coupling factors, correlated with higher mechanical quality factors, compared to the rest of materials. Hard-like piezoelectric behavior was manifested in materials with Ni–Nb AV 4+, and without manganese, turned out to have a soft-like behavior. Electromechanical properties of PT ceramics are discussed in terms of average valence of Ni–Nb co-dopants and multivalence state of manganese.

Dielectric, structural and pyroelectric properties of the Pb0.525Ca0.475TiO3 (PCT47.5) ceramic system were investigated for temperatures ranging from cryogenic up to 570 K. Two anomalies were observed in the temperature dependence of the dielectric permittivity and of the pyroelectric coefficient. A structural refinement study based on the powder XRD data revealed that a distorted perovskite structure with orthorhombic symmetry in space group Pbnm was the best fitting for the entire temperature range analyzed. Nevertheless, the analysis protocol showed that the temperature dependence of the refined lattice parameters is very sensitive to the phase transitions, allowing the association of such transitions to the anomalies observed in the electric properties.

The glass samples with composition 37.5PbO:37.5TiO2:22.5B2O3:2.5SiO2 were synthesized by conventional melt quenching technique. These glasses were converted to glass–ceramic by following the two stage heat treatment, by varying systematically the duration of heat treatment. The density, dielectric constant and dielectric loss of glass and glass–ceramic samples were measured. The density and dielectric constant of the glass–ceramic samples were observed to increase with the heat treatment duration up to 32 h. The glass–ceramic samples exhibited ferroelectric hysteresis due to the presence of PbTiO3 crystals as confirmed from XRD. From the results it can be concluded that 32 h heat treatment duration is optimum for getting PbTiO3 glass–ceramic. The high temperature ferroelectric hysteresis measurements have been carried out for the optimized (32 h) glass–ceramic sample. The exhibition of ferroelectric behaviour up to 250 °C indicates the possibility of utilization of this sample for high temperature transducer applications.

The objective of this work is to derive the full material constants of an equivalent single phase material to replace the complex-structured PMN-28%PT (lead magnesium niobate-28%lead titanate)/epoxy 1–3 composite in finite element analysis (FEA) of acoustic transducers. No attempts have been made to derive full material constants of the homogenized PMN-PT/epoxy piezocomposites. In this study, the equivalent properties were derived by extensive resonance analyses and the FEM. The PMN-28%PT crystals have tetragonal 4 mm symmetry and thus have eleven independent material constants in total. FE models of piezocomposite resonators of six different configurations were constructed to analyze all possible vibration modes of the composite. All the material constants of the equivalent single phase material were extracted from the simulation data with the FE models so that the equivalent material can have identical resonant characteristics as the full complex-structured PMN-PT/epoxy composite. The validity of the homogenization technique and the accuracy of the equivalent material constants were verified by comparing the impedance spectra of the single phase resonators with those of the full-structured piezocomposite resonators. The accuracy and efficacy of the homogenized material constants was verified further by comparing the performance of multi-layered hydrophones made of the full-structured 1–3 piezocomposite as well as the equivalent single phase material. The homogenization procedure can be applied to 1–3 piezocomposites with an arbitrary volume fraction of the PMN-PT single crystal.

A series of Lead Titanate ceramic with various concentration of Calcium has been prepared by solid state reaction method, and some of their physical properties and structural characteristics have been studied. The incorporation of small amount of Calcium results in considerable changes in the dc electrical conductivity and the temperature of the ferroelectric phase transition. Lead Titanate (PT) is a well known ferroelectric with high curie point and low dielectric thus constant making it an attractive proportion for various applications. The synthesis of Calcium modified PbTiO3 was carried using solid state reaction method. Stoichiometric amount of high purity CaO was used as a dopant in different proportion and the final product was in powder form. The X-ray diffraction pattern was taken for pure and CaO modified Lead Titanate. The SEM of the sample was done on JEOL 6360A Analytical Scanning Electron Microscope. There is an observable change in grain size with different molar concentration of Calcium oxide. The DC conductivity of the sample was carried out using two probe method over a range of temperature covering their transition temperature.