Showing papers on "Lead zirconate titanate published in 1996"
TL;DR: In this article, the Rayleigh effect was applied to irreversible displacement of several types of non- ferroelectric domain walls and imply universal validity of Rayleigh law for displacement of ferromagnetic and ferroelastic domain walls.
Abstract: The direct longitudinal piezoelectric effect in lead zirconate titanate, barium titanate, bismuth titanate and strontium bismuth titanate ceramics was investigated with respect to the dependence on the amplitude of an alternating pressure. At low alternating pressure amplitudes, the behaviour of the piezoelectric charge and the piezoelectric coefficient may be explained in terms of the Rayleigh law originally discovered for magnetization and magnetic permeability in ferromagnetic materials. The charge versus pressure hysteresis loops measured for piezeoelectric ceramics may similarly be described as the Rayleigh loops. The results presented show that the Rayleigh law can be applied to irreversible displacement of several types of non- ferroelectric domain walls and imply universal validity of the Rayleigh law for displacement of ferromagnetic, ferroelastic and ferroelectric domain walls.
284 citations
TL;DR: In this article, a new scanning technique for imaging the state of spontaneous polarization of a ferroelectric material by measuring the microscopic point-to-point variation of its nonlinear dielectric constants is described.
Abstract: This article describes a new scanning technique for imaging the state of spontaneous polarization of a ferroelectric material by measuring the microscopic point‐to‐point variation of its nonlinear dielectric constants. First, the theory for detecting polarization is described. Second, the technique for measuring the nonlinear dielectric response is described. Finally, using this new microscope, area scans are obtained of the polarization of poled lead zirconate titanate ceramics, a lithium niobate single crystal, and of piezoelectric thin films of the copolymer of vinylidene fluoride and trifluoroethylene.
215 citations
TL;DR: In this article, the thickness dependence of film structure and the dielectric, ferroelectric, and piezoelectric properties have been characterized over the thickness range of 1-12 μm.
Abstract: Thick films of lead zirconate titanate of the morphotropic phase boundary composition, Pb(Zr0.52Ti0.48)O3, have been fabricated on platinum-buffered silicon using a modified sol–gel spin-coating technique. Crack-free films of 12-μm thickness can be uniformly deposited on 3-in.-diameter wafers with high yield and properties comparable to those of bulk ceramics. The thickness dependence of film structure and the dielectric, ferroelectric, and piezoelectric properties have been characterized over the thickness range of 1–12 μm. A strong (100) texture develops as film thickness increases above 5 μm; the films were marked by saturation values of longitudinal piezoelectric coefficient d33, 340 pC/N; remanent polarization, 27 μC/cm2; and dielectric permittivity, 1450. PZT films in this thickness range are extremely well-suited to application as electromechanical transduction media in silicon-based microelectromechanical systems (MEMS).
134 citations
TL;DR: In this article, Lanthanum modified lead zirconate titanate (PLZT) ceramics near a crossover between normal and relaxor ferroelectric states for Zr/Ti ratios of 40/60, 20/80, and 0/100 were investigated by dielectric spectroscopy, Sawyer-tower polarization techniques and transmission electron microscopy.
Abstract: Lanthanum modified lead zirconate titanate (PLZT) ceramics near a crossover between normal and relaxor ferroelectric states for Zr/Ti ratios of 40/60, 20/80, and 0/100 were investigated by dielectric spectroscopy, Sawyer–Tower polarization techniques and transmission electron microscopy. It was found possible to induce a relaxor state in each of these tetragonal PLZT compositional sequences with increasing La content. The transformation between normal and relaxor‐like behaviors was found to be associated with a domain evolution from normal micron‐sized domains, to tweed‐like subdomain structures, and finally to polar nanodomains. A spontaneous relaxor to normal transformation was found near a critical La content in each compositional sequence. Temperature dependent polarization studies revealed a field‐induced relaxor to normal ferroelectric transition at temperatures above that of the spontaneous transformation.
107 citations
TL;DR: The role of precursor stoichiometry and local firing environment on the microstructural development of sol-gel derived lead zirconate titanate (PZT) thin films was investigated in this article.
Abstract: The role of precursor stoichiometry and local firing environment on the microstructural development of sol-gel derived lead zirconate titanate (PZT) thin films was investigated. Typically, excess Pb is added to films to compensate for PbO volatilization during heat treatment. Here, it is shown that the use of stoichiometric precursors with either a PbO atmosphere powder or a PbO overcoat during the crystallization heat treatment is an attractive and viable alternative method for control of film stoichiometry. Using these approaches, we have fabricated single phase perovskite thin films with microstructures and electrical properties (Pr ∼ 36 μC/cm2 and Ec ∼ 45 kV /cm) comparable to those of films using optimized solution chemistries and excess Pb additions. The potential advantage of increasing PbO partial pressure, or activity, during firing versus excess Pb additions is discussed from the standpoint of a proposed crystallization scenario based on the kinetic competition between Pb loss and the nucleation and growth rates of the perovskite phase.
92 citations
TL;DR: In this article, a micromachined lead zirconate titanate (PZT) force sensor for scanning force microscope (SFM) is conceptualized by its piezoelectricity.
Abstract: A micromachined lead zirconate titanate (PZT) force sensor for scanning force microscope (SFM) is conceptualized by its piezoelectricity. The fabrication procedure is interpreted, and mechanical characteristics of the micromachined PZT force sensors with various lengths are studied in this paper. A compact SFM is constructed by using the piezoelectric PZT sensor. A very clear image is taken by this SFM. The current study of the micromachined PZT force sensor can be considered as a breakthrough of design of SFM as well as a good example of integrated piezoelectric microdevices.
84 citations
TL;DR: In this paper, the effects of low-temperature processing on texture development were investigated. And the profound influence of low temperature processing steps, hitherto assumed benign from the viewpoint of texture development, was reported.
Abstract: The profound influence of low-temperature processing steps, hitherto assumed benign from the viewpoint of texture development, is reported. On inclusion of a 400°C step and further heat treatment at 700°C, PZT (40/60) sol-gel thin films with a strong (111) texture were obtained. When the 400°C step was excluded, the films exhibited a strong (100) texture. The (111) PZT texture development is nucleation-controlled and is attributed to the solid-phase epitaxial effect. The (100) texture is considered growth-controlled in that (100) oriented grains grow preferentially so as to minimize surface energy.
84 citations
TL;DR: Ferroelectric memories have been known for a long time, and the idea to use them for binary data storage originates in the 1950s as discussed by the authors, however, early prototypes were unsuccessful because rather high voltages were needed to switch the ferroelectric capacitor (200-300 V) and the memories suffered from crosstalk.
Abstract: A nonconventional way of producing nonvolatile memories is to use ferroelectrics, a class of electroceramic materials. These materials have a remanent polarization. The direction of this polarization can be changed by an electric field. Ferroelectric materials possess a “natural memory,” so to speak. Ferroelectrics have been known for a long time, and the idea to use them for binary data storage originates in the 1950s. The basic element of this type of memory is formed by a ferroelectric capacitor—a ferroelectric layer sandwiched between electrodes. Early prototypes were unsuccessful because rather high voltages were needed to switch the ferroelectric capacitor (200–300 V) and the memories suffered from crosstalk. (Programming one particular cell influenced neighboring cells.) The revival of ferroelectric memories was driven by the development of thin-film deposition techniques that allowed the formation of capacitors with ferroelectric thin films of submicron thicknesses. These capacitors can be switched with normal intergrated-circuit (IC) voltages. The crosstalk problem is circumvented by isolating each memory cell by a transistor (similar to a dynamic random-access memory [DRAM]). Compared to “standard” nonvolatile memories, ferroelectric memories offer the advantage of very fast access times (both for reading and writing), low-voltage operation, and good write/read endurance. A ferroelectric material that is already being used in commercially available memories is lead zirconate titanate, PbZrxTi 1−xO3. To combine a ferroelectric material with IC technology is a challenge, and many problems have been (and will be) encountered.
74 citations
TL;DR: In this paper, the longitudinal direct piezoelectric effect in ceramics based on lead zirconate titanate, lead titanate and barium titanate is investigated as a function of the amplitude and frequency of the external pressure, the crystal structure and microstructure of the poramics.
Abstract: The large piezoelectric effect of ferroelectric ceramics is utilized in many devices for sensing and actuating purposes. In this paper, the longitudinal direct piezoelectric effect in ceramics based on lead zirconate titanate, lead titanate, barium titanate and bismuth titanate is investigated as a function of the amplitude and frequency of the external pressure, the crystal structure and microstructure of the ceramics. The domain-wall contribution to the piezoelectric response appears to be a dominant extrinsic origin of instabilities in the observed piezoelectric effect but, for a given composition, it can be affected by dopants and microstructure. Other sources of instabilities in the piezoelectric response, such as chemical inhomogeneities and defects, are also discussed. It is shown that, with proper modifications, it is possible to freeze out completely the extrinsic part of the piezoelectric response in some of the examined compositions and to obtain a stable behaviour, independent of the frequency and magnitude of the external driving field.
74 citations
TL;DR: In this article, the effect of mechanical cycling and electrical cycling on the degradation of PZT-8 bars was examined using TEM and energy-dispersive spectroscopy.
Abstract: The effect of mechanical cycling (four-point bending) and electrical cycling (ac excitation at the longitudinal resonance frequency) on the degradation of the mechanical properties of PZT-8 bars was examined. Transmission electron microscopy (TEM) revealed microcracks which originated from second-phase material located at triple junctions. Energy-dispersive spectroscopy (EDS) showed that this second-phase material contained Pb, Ti, and Fe, but no detectable Zr. High intergranular microcrack densities were observed for mechanically cycled samples and samples electrically cycled at temperatures ≤80°C. Electrically cycled samples allowed to heat to a steady-state temperature of 180°C showed much lower crack densities. Piezoelectric coefficient (d33) measurements revealed that depolarization occurs in the 180°C electrically cycled samples, but not in mechanically cycled materials nor in the 80°C electrically cycled material. Also, samples heated in a furnace to 180°C in the absence of external stress showed no evidence of depolarization. It appears that elevated temperatures (∼180°C) are necessary to cause depolarization in PZT-8 at the resonance-induced stresses used in this work.
72 citations
TL;DR: In this paper, an atomic force microscope (AFM) with a batch-fabricated silicon cantilever with a pyramidal stylus has been successfully developed, where the high quality lead zirconate titanate (PZT) piezoelectric thin film allows simultaneously displacement sensing and actuating.
Abstract: We successfully developed an atomic force microscope (AFM) with a batch‐fabricated silicon cantilever with a pyramidal stylus. The high quality lead zirconate titanate (PZT) piezoelectric thin film allows simultaneously displacement sensing and actuating. The PZT thin film with a dielectric constant of 1000, a remanent polarization of 30 μC/cm2, and a piezoelectric constant of −100 pC/N, which are as high as those of bulk ceramics PZT, has been formed by sputtering at 400 °C and subsequent annealing at 650 °C. A Si(111) mono‐atomic step whose height is 4 A has been observed clearly in an AFM cyclic contact mode by a PZT‐AFM lever as a displacement sensor. A PZT‐AFM lever has been used as an actuator for z feedback positioning for AFM imaging of a compact disk pit.
TL;DR: In this paper, a Raman study of lead zirconate titanate ceramics with La/Zr/Ti ratios of 9/65/35 and 12/40/60 has been undertaken in order to compare the onset of ferroelectric order in these two compositions.
Abstract: A Raman study of La‐doped lead zirconate titanate ceramics with La/Zr/Ti ratios of 9/65/35 and 12/40/60 has been undertaken in order to compare the onset of ferroelectric order in these two compositions. Some features, such as a splitting of a threefold degenerate T1u mode of the cubic structure into at least two lines or an enhancement of the T2u mode, can be considered as the signature of the occurrence of some ferroelectric order below Tc≂363 K in the 12/40/60 compound. Nevertheless, the Raman spectra obtained for the two ceramics are very similar, and no significant narrowing of the lines was observed in the ferroelectric phase of 12/40/60. It is thus suggested that the onset of long range order in this compound is not developed homogeneously in every direction of space, in agreement with previous transmission electron microscopy observations. The Raman scattering was dominately second order, with the broadening of the lines reflecting a distribution of the correlation function of the quasistatic pola...
TL;DR: In this paper, the authors characterized prototypes of NDRO NVRO devices which utilize semiconducting In2O3 deposited on thin film lead zirconate titanate and bulk BaTiO3 FEs.
Abstract: The electric field emanating from the surface of a poled ferroelectric (FE) can control the conduction properties of an overlying semiconducting (SC) film; this combination of materials can thus serve as a nondestructive readout (NDRO), nonvolatile memory device. We have characterized prototypes of these devices which utilize semiconducting In2O3 deposited on thin film lead zirconate titanate and bulk BaTiO3 FEs. The remanent state SC resistance in thin film FE NDRO devices is often opposite to that predicted from the known direction of FE polarization. In these cases charge injected from the SC film into the FE and trapped near the interface appears to control the electric field at the SC/FE interface. By contrast, the response of SC films on bulk FEs is largely controlled by just the FE remanent polarization. The measured SC resistance values in the ‘‘up’’ and ‘‘down’’ polarization states can be fairly accurately predicted by calculating the accumulation and depletion charge densities from the measured ...
Patent•
09 Dec 1996TL;DR: In this paper, a method for forming a crystalline perovskite phase of a ferroelectric dielectric material by annealing in an oxygen containing atmosphere in the presence of water vapor, preferably with the addition of a few percent of ozone and at a temperature of less than 500°C.
Abstract: A method is provided for forming a crystalline perovskite phase of a ferroelectric dielectric material by a process of depositing a layer of amorphous ferroelectric precursor material and then annealing in an oxygen containing atmosphere in the presence of water vapor, preferably with the addition of a few percent of ozone and at a temperature of less than 500° C. Advantageously, the method provides for formation of a ferroelectric material comprising lead zirconate titanate, with low film stress, high dielectric constant and low leakage current. The reduced thermal budget allows for increase flexibility in integration of ferroelectric materials, e.g. after a step of deposition of low melting point metal or metal alloy.
TL;DR: In this paper, a sol-gel preparation of Pb(Zr0.53Ti0.47)O3 (PZT) thin films is described, which involves the insertion of an in situ crystallizing interlayer film of perovskite lead titanate (PT) as a seeding layer that offers nucleation sites which lower the activation energy for crystallization.
Abstract: A novel method is developed for the sol-gel preparation of Pb(Zr0.53Ti0.47)O3 (PZT) thin films. This method involves the insertion of an in situ crystallizing interlayer film of perovskite lead titanate (PT) as a seeding layer that offers nucleation sites which lower the activation energy for crystallization. Highly crystallized PZT films with the perovskite structure were successfully obtained on Pt-coated silicon wafers and even on silica-glass substrate. The formation temperature of a perovskite single phase in the PZT thin film was effectively lowered to 500° C in air and 450° C in a mixture of water vapor and oxygen. Relative permittivity, e r, of the resultant films annealed below 500° C increased with increasing film thickness and leveled off at around 1.5 µ m thickness. e r saturated at around 500 at 1 kHz. This behavior was compared with those of films prepared by other methods at relatively high temperatures. It was concluded that the molecular design of the alkoxide precursor solution and the use of an in situ crystallizing PT seeding layer were essential for lowering the crystallization temperature as well as for obtaining good electrical properties of the resultant PZT thin films.
TL;DR: In this paper, the antiferroelectric (AFE) and ferroelectric phase transformation under dc bias and hydrostatic pressure conditions in tin-modified lead zirconate titanate ceramics [Pb(Zr,Sn,Ti)O3] was investigated.
Abstract: The antiferroelectric (AFE)‐ferroelectric (FE) phase transformation under dc bias and hydrostatic pressure conditions in tin‐modified lead zirconate titanate ceramics [Pb(Zr,Sn,Ti)O3, i.e., PZST] was investigated. The shifting of transformation temperature under these conditions and an electric field induced lattice softening are reported. Depending on the symmetry of external applied fields, the thermal stability region of one phase can be expanded at the expense of another. Experimental results indicate that a symmetric external field (such as hydrostatic pressure) tends to stabilize the AFE phase region, whereas an asymmetric external field (such as electric field) tends to extend the FE phase region. These observations are found to be generally consistent with many ferroelectric and antiferroelectric materials exhibiting a displacive structural phase transformation. Results are compared with the Clausius–Clapeyron relationship, and fundamental issues underlying the thermodynamic relationship and field...
TL;DR: An atomic force microscope cantilever with PZT thin film with pyramidal stylus was used for actuation of feedback motion as discussed by the authors, and the maximum stroke was more than 1 μm within a frequency range from direct current up to natural resonant frequency, e.g., 28.48 kHz.
Abstract: An atomic force microscope cantilever with PZT thin film with pyramidal stylus was used for actuation of feedback motion. The maximum stroke of the cantilever was more than 1 μm within a frequency range from direct current up to natural resonant frequency, e.g., 28.48 kHz. An image of a pit of a compact disk with a depth of 100 nm was successfully obtained using only cantilever actuation in a vertical direction.
TL;DR: In this article, the microstructure of PbZrxTi1−xO3 films on (001)SrTiO3 was studied as a function of the zirconium fraction, x.
Abstract: PbZrxTi1−xO3 films have been grown heteroepitaxially onto (001)SrTiO3 and SrRuO3/(001)SrTiO3 by organometallic chemical vapor deposition. As a start, the microstructure of PbZrxTi1−xO3 films on (001)SrTiO3 was studied as a function of the zirconium fraction, x. Rutherford backscattering spectrometry, including channeling experiments, and transmission electron microscopy have shown that the microstructure is dominated by the crystal structure of the PbZrxTi1−xO3. In the case of tetragonal PbZrxTi1−xO3 the films may contain a‐axis oriented regions. These regions have not been observed for films with a composition giving a rhombohedral unit cell. Despite the rather large mismatch of rhombohedral PbZrxTi1−xO3 with the (001)SrTiO3, values as low as 4% for the minimum channeling yield have been obtained. For a rhombohedral film the ferroelectric properties have been measured. To this end a single crystalline PbZr0.8Ti0.2O3 film was grown onto (001)SrTiO3 provided with a heteroepitaxial SrRuO3 electrode grown by...
TL;DR: In this article, an antiferroelectric-ferroelectric (AFEIn) phase was found to be stabilized from the rhombohedral FE state in the compositional series 100x/90/10 for x ≥ 0.02.
Abstract: Lanthanum-modified lead zirconate titanate ceramics Pb1−3/2xLax(Zr1−yTiy)O3 [PLZT 100x/100(1 − y)/100y] with Zr/Ti ratios close to the antiferroelectric-ferroelectric (AFE-FE) phase boundary were investigated by dielectric spectroscopy, Sawyer–Tower polarization techniques, and electron microscopy. An incommensurate antiferroelectric (AFEIn) phase was found to be stabilized from the rhombohedral FE state in the compositional series 100x/90/10 for x ≥ 0.02. The La content required to induce the AFEIn state increased as the Ti content was increased. For 100x/85/15, a state with relaxor-like dielectric behavior and nanodomains was observed to develop with increasing La content; however, the double-loop-like P-E curves were suggestive of antiferroelectric behavior. Investigations for the composition 6/85/15 revealed the formation of nanodomains from the AFEIn modulation, where the size of the nanodomains equaled the value of the AFEIn modulation wavelength. For this composition, P-E studies revealed double hysteresis characteristics, whereas dielectric investigations revealed relaxor-like behavior. It is suggested that the order within the nanodomain state may be antipolar over a range of compositions in high La content rhombohedral PLZT ceramics.
TL;DR: In this article, a 20mol% Pb excess PZT film has good piezoelectric properties, and the dielectric constant, the piezeric constant d31 and the spontaneous polarization Ps are 1800, 30.0×10-2C/m2 and 39.2× 10-12C/N, respectively.
Abstract: PZT thin films for microsensors and microactuators were prepared from lead acetate and zirconium, titanium alkoxide solution by sol-gel processing. High-performance, crack-free, thin (3.1μm) films were acquired by multiple coating, and high-temperture annealing.PbO evaporation occurred on firing. This is caused by the lack of Pb and the structure is divided into a perovskite phase and the amorphous and/or nanocrystal regions. The existence of the amorphous and/or nanocrystal region reduces the dielectric and piezoelectric constants. Excess Pb diminishes the amorphous and/or nanocrystal region and improves the piezoelectric and ferroelectric properties.A 20mol% Pb excess PZT film has good piezoelectric properties. The dielectric constant er, the piezoelectric constant d31 and the spontaneous polarization Ps are 1800, 30.0×10-2C/m2 and 39.2×10-12C/N, respectively. These values are similar to those of bulk PZT ceramics. This PZT film will be used in the fabrication of microactuators and microsensors.
TL;DR: In this paper, a short group-theoretical discussion is given of phonon symmetries in different phases of the Pb(ZrxTi1−x)O3 (PZT) perovskite together with a description of the degeneracy splitting in consequence of the long-range Coulomb fields both in the paraelectric cubic phase and ferroelectric tetragonal and trigonal phases.
Abstract: A short group‐theoretical discussion is given of phonon symmetries in different phases of the Pb(ZrxTi1−x)O3 (PZT) perovskite together with a description of the degeneracy splitting in consequence of the long‐range Coulomb fields both in the paraelectric cubic phase and ferroelectric tetragonal and trigonal phases. Phonon symmetries together with the frequency splitting are used for the consideration of Raman modes, measured from Nd‐doped PZT thin films with Zr concentrations below or near to the morphotropic phase boundary between the ferroelectric tetragonal and trigonal phases. Raman spectroscopy was used in addition to x‐ray diffraction experiments for the characterization of the phase structure in the films. Raman spectra were measured at room temperature and also at some higher temperatures up to 318 °C. A XeCl‐excimer laser was used for the pulsed laser ablation of thin films from a Pb0.97Nd0.02(Zr0.55Ti0.45)O3 target on sapphire and MgO substrates without substrate heating. After ablation, the amo...
TL;DR: In this article, the switching endurance properties of lead-zirconate-titanate thin-film capacitors with gold, platinum and iridium top electrodes were investigated using a pulse switching characterization technique.
Abstract: Switching endurance properties of lead-zirconate-titanate thin-film capacitors with gold, platinum and iridium top electrodes were investigated using a pulse switching characterization technique. Lead-zirconate-titanate capacitor structure formed with Ir top and bottom electrodes exhibited superior switching endurance to Au/PZT/Ir and Pt/PZT/Ir capacitors. The difference between switched and nonswitched polarizations of an Ir/PZT/Ir capacitor reversed by bipolar pulses was more than 38 µ C/ cm2 after 2×109 switching cycles. Nonswitched polarization of this capacitor for negative read-pulses decreased gradually with increase in the number of switching cycles. When positive and negative unipolar pulses, and DC biases were applied to the top electrodes of Pt/PZT/Ir and Ir/PZT/Ir capacitors, remanent polarizations of each capacitor were not changed significantly. However, nonswitched polarizations for negative read-pulses decreased with increase in the number of negative unipolar pulses applied or DC bias application time. Drastic decrease in remanent polarization of a Pt/PZT/Ir capacitor was caused only by bipolar pulse application. The reduction of nonswitched polarization for negative read-pulses suggested the formation of depletion-layer capacitances at the interfaces between top electrodes and PZT layers.
TL;DR: In this paper, Lanthanum modified lead zirconate titanate (PLZT) ceramics with a Zr/Ti ratio of 85/15 were investigated as a function of La content by dielectric spectroscopy, Sawyer-Tower polarization techniques, and electron microscopy.
Abstract: Lanthanum modified lead zirconate titanate (PLZT) ceramics with a Zr/Ti ratio of 85/15 were investigated as a function of La content by dielectric spectroscopy, Sawyer–Tower polarization techniques, and electron microscopy. Tweedlike structures were found to evolve from normal μm‐sized ferroelectric domains with increasing La content above 4 at. %. For a composition with 6 at. % La, an incommensurate antiferroelectric state was found to coexist with a polar nanodomain state, where the size of the nanodomains was approximately equal to the value of the incommensurate modulation wavelength. For this composition, P–E studies revealed double hysteresis characteristics, whereas dielectric investigations revealed relaxorlike ferroelectric behavior.
TL;DR: In this article, a transition between a disordered R-type tilted state to a low temperature ordered R- type tilted state was found near the FER(HT)-FER(LT) boundary.
TL;DR: In this article, the structure properties of lead zirconate titanate have been investigated as a function of the concentration of lower-valent A-site substitution and the dielectric response with increasing K 1+ concentration.
Abstract: Studies of the structure‐property relationships have been performed for lead zirconate titanate as a function of concentration of a lower‐valent A‐site substitution. Investigations focused on the system (Pb1−yKy)(Zr0.65Ti0.35)O3−y/2 for 0
TL;DR: The phase formation mechanism of lead zirconate titanate (PZT) processed by a partial oxalate method was investigated by simultaneous thermal analysis (TG-DTA) and by qualitative and quantitative X-ray diffraction (XRD).
Abstract: The phase formation mechanism, as well as the morpho-tropic phase boundary, of lead zirconate titanate (PZT) processed by a partial oxalate method was investigated by simultaneous thermal analysis (TG-DTA) and by qualitative and quantitative X-ray diffraction (XRD). The results show that the ZrxTi1–xO2 (ZT) phase reacts with PbO forming the PZT phase without intermediate phases. XRD analysis showed the coexistence of rhombohedral and tetragonal phases for 0.47 ≤x≤ 0.55 with the phase boundary composition for x= 0.51. For low calcination temperatures, preferential formation of the PZT rhombohedral phase was observed. A model for phase formation of PZT by the partial oxalate method is proposed based on the existence of two interfaces of reaction (PbO-PZT and PZT-ZT) and diffusion of cations.
TL;DR: In this paper, the structural development, spectroscopic, and dielectric properties of PZT 40/60 thin films have been systematically investigated using atomic force microscopy (AFM), x-ray diffraction, Fourier transform infrared spectroscopy, Raman scattering, and DVS measurements.
Abstract: Pin‐hole free ferroelectric (Pb,La)(Zr1−xTix)O3 thin films with uniform composition have been fabricated using the metallo‐organic precursor compounds, which were carefully home synthesized. The structural development, spectroscopic, and dielectric properties of these films have been systematically investigated using atomic force microscopy (AFM), x‐ray diffraction, Fourier transform infrared spectroscopy, Raman scattering, and dielectric measurements. It has been found from our experimental results of PZT 40/60 thin films that the overlapping of (h00) and (00l) peaks of these films in x‐ray diffraction patterns, mainly due to the small grain sizes in films, makes it very difficult to distinguish individual diffraction peaks and to identify the phases. However, Raman measurements undoubtedly reveal the Raman spectra of these films in the tetragonal phase field, demonstrating that Raman spectroscopy is an effective tool to identify structures, especially in the case of thin films having very small grains. ...
TL;DR: In this article, the ferroelectric domain structures of tetragonal lead zirconate titanate (PZT) ceramics were evaluated by investigating the poling field (E) dependence of the planar coupling factor (k p ) and the relative intensity of X-ray diffraction (002) peak, I 002.
Abstract: The ferroelectric domain structures of tetragonal lead zirconate titanate (PZT) ceramics were evaluated by investigating the poling field (E) dependence of the planar coupling factor (k p ) and the relative intensity of X-ray diffraction (002) peak, I 002 . Fifteen typical domain configurations were proposed. Furthermore, we selected the two patterns which make a domain configuration model with 90° and 180° domains. It was thought that the change in domain structure due to poling could be explained by calculating the change in area of domain for each axis. Therefore, the total number of domains oriented along the c axis was estimated from using the relationship between I 002 , k p , the normalized polarization and E. Using our domain configuration model, it was confirmed that there were two peaks corresponding to 90° domain rotation and one peak corresponding to 180° domain switching. After the 90° domain rotation occurred, the domains along the c axis were changed mainly by 180° switching. As a result, the degree of 90° domain rotation decreased and that of 180° domain switching increased. Our study on domain structures in bulk ceramics is useful for understanding the degradation characteristics of PZT thin films.
TL;DR: In this paper, the rate of combustion controlled the growth of the oxide particles, which can be manifested by combustion of the mixture in controlled atmosphere, in order to obtain the desired oxide phase.
Abstract: Fine powder of single and binary mixed oxides can be produced by decomposition of the respective metal nitrates and polyvinyl alcohol (PVA) or, a mixture of PVA and polyacrylic acids. These mixtures, after spray drying, yield a brown fluffy mass, which is spontaneously combustible and the heat liberated is sufficient for the crystallization of the desired oxide phase. The rate of combustion controls the growth of the particles. This can be manifested by combustion of the mixture in controlled atmosphere. The nanoparticles of the oxide system studied are: spinels [MFe2O4 where M = Ni(II), Co(II), Zn(II), Mg(II)]; orthoferrites [MFeO3 where M = Gd(III), Sm(III)]; LaAlO3, NdGaO3, CaO/MgO/Y2O3 stabilized zirconia (ZrO2); lead zirconate titanate (PZT), lanthanum modified lead zirconate titanate (PLZT) and BaTiO3.