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The short-circuit photocurrent (SC-PHC) in the 200-800 nm wavelength domain was used to investigate the photovoltaic properties of the metal-ferroelectric-metal structures having SrRu[O.sub.3] metal oxide electrodes and Pb(Zr, Ti)[O.sub.3] (PZT) as ferroelectric layer. The band-gap energies evaluated from the PHC spectral distribution for different PZT compositions range between 3.9 to 4.4 eV and it is constantly higher than the reported experimental values on polycrystalline films but agree well with theoretical values.

The effect of Ta substitution on the structural, microstructural, molecular and dielectric characteristics of Pb[Sc(sub)0.5Nb(sub)0.5]O(sub)3 (PSNT), synthesized by mechano-synthesis and conventional mixed oxide methods is studied. It is found that the ceramics show the formation of the materials in a single phase in the rhombohedral structure with the existence of nanodomain.

Various x-ray diffraction experiments are employed to study the microscopic-scale structures of 0.72Pb([Mg.sub.1/3][Nb.sub.2/3])[O.sub.3]-0.28PbTi[O.sub.3] relaxor ferroelectrics in a high external dc field during phase transition. The results clearly prove that a change in the temperature also leads to a major change in the dominating cluster's orientation, as well as their interaction direction.

Relaxor-type ferroelectric (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) films, 2-3 mum in thickness, with a PbTiO3 content (x) ranging from 0 to 1 were grown on [(100).sub.c]SrRuO3 ll (100)SrTiO3 substrates at 650 degree Celsius by metal-organic chemical vapor deposition. The constituent phase changed from a rhombohedral (pseudocubic) single phase, a mixture phase of rhombohedral (pseudocubic) and tetragonal phases, and a tetragonal single phase, with increasing x.

Relaxor-type ferroelectric (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) films, 2-3 mum in thickness, with a PbTiO3 content (x) ranging from 0 to 1 were grown on [(100).sub.c]SrRuO3 ll (100)SrTiO3 substrates at 650 degree Celsius by metal-organic chemical vapor deposition. The constituent phase changed from a rhombohedral (pseudocubic) single phase, a mixture phase of rhombohedral (pseudocubic) and tetragonal phases, and a tetragonal single phase, with increasing x.

The dependence of the domain structure on poling for (001)-oriented Pb(Mg1/3Nb2/3)O3-x%PbTiO3 crystals is discussed by scanning force microscopy in the piezoresponse mode and by polarized optical microscopy. The results demonstrate a domain hierarchy on various length scales, ranging from nanometers to millimeters, which is notably dependent upon the electrical history of the specimen.

A study is carried out on the crystal structure and dielectric properties of (1-x)Pb(Yb1/2Nb1/2)O3-Pb(Sc1/2Nb1/2)O3 (PYN(1-x)PSNx) (O less than or equal to x less than or equal to 0.60) solid solution. Details of its pseudobinary phase diagram are determined.

The fabrication and properties of the porous lead zirconate titanate ceramics with one dimensional ordered pore structure are analyzed. The piezoelectric and dielectric properties of the ceramics are shown to get reduced because of the special structure.

Lead zirconate titanate (Pb[Zr.sub.0.52][Ti.sub.0.48][O.sub.3]-PZT) thin films with different thicknesses are deposited on Pt(111)/Ti/Si[O.sub.2]/Si substrates by using sol-gel method. The scanning force microscopy is used for studying the effect of thickness on the microscopic piezoresponse and the differences between the macroscopic and microscopic electrical properties of the films are assigned to changes in the nonswitching film-electrode layer and domain structure.

The article presents a complete analysis of the technology used for the fabrication of the two-dimensional photonic crystal (PhC) band edge lasers that are found to be operating at the terahertz frequencies. The photonic band structure of the system is shown to be the main determinant of its lasing properties.

The magnetoelectric (ME) response and magnetic-field sensitivities of engineered laminate sensors comprised of magnetostrictive and piezoelectric phases are compared. The studies have resulted in the enhancement in the magnetic-field sensitivity for the structures with single crystals and the noise floors are lower for composites with Pb([Mn.sub.1/3][Nb.sub.2/3])[O.sub.3]-PbTi[O.sub.3] (PMN-PT) or Pb([Zn.sub.1/3][Nb.sub.2/3])[O.sub.3]-PbTi[O.sub.3] (PZN-PT) fibers than those with Pb(Zr,Ti)[O.sub.3] (PZT).

Lead zirconate titanate (PZT) stacks that have an interdigital internal electrode configuration are tested and significant reductions in piezoelectric and dielectric responses are observed during the cycling depending on the measuring condition. The results have shown the feasibility of using a semibipolar mode to drive a PZT stack under a mechanical preload and also display the potential fatigue and damages of the stack in service.

The possible mechanisms of phonon scattering by nanostructures and defects in PbTe-X (X = 2%Sb, Bi, or Pb) thermoelectric materials systems are examined. The particle-induced local elastic perturbations have interfered with the phonon propagation pathway, thereby contributing to the reduction in lattice thermal conductivity and increasing the overall thermoelectric figure of merit.

The stability of various crystallographic phases of (1-x)BiFe[O.sub.3]-xPbTi[O.sub.3] is studied as a function of composition and temperature. The comparison between the bon lengths between oxygen and other cations has shown that the very high c/a ratio in the tetragonal phase of the system is linked with the covalency effects for bonding between both A and B site cations with oxygen.

The generation of charge in thin piezoelectric structures is measured and modeled under sinusoidal hydrostatic pressure and has also shown the domination of the subsequent thermally induced pyroelectric effect on the response in the smallest samples. The analysis of the piezoelectric and pyroelectric charge response has major impact on the design and functional behavior of small-scale piezoelectric devices.

The formation of various isostructural inorganic-organic hybrid ferroelectric compounds from the aggregation of the [[Pb[I.sub.3]].sub.delta] chains directed organic cations to Kagome-shaped tubular architecture is discussed. The large spontaneous polarizations exhibited by these compounds are also explained.

The temperature dependence of the visible fluorescence lines of large Pb[F.sub.2] nanocrystals codoped with [Er.sup.3+] and [Yb.sup.3+] ions is studied. The studies have shown that the fluorescence is affected both by the near-field optical distribution and by temperature variations.

The article studies the monolithically integrated bifunctional frontplane element based on a composite foil of piezoelectric ceramic lead titanate nanoparticles embedded in ferroelectric poly polymer matrix. Findings highlight multifunctional frontplanes for large area electronic surfaces.

The dielectric and ferroelectirc properties of (1-x)Pb([Mg.sub.1/3][Nb.sub.2/3])[(O.sub.3]-(x)PbTi[O.sub.3] ((1-x)PMN-(x)-PT) (x=0.1-0.4) ceramics are measured under compressive stress applied perpendicular to the electric field. The influences of the stress applied in the perpendicular direction to the electric field are opposite to those of the parallel stress.

The effects of Ta content on the phase transitional behavior, Raman spectrum, microstructure and dielectric, piezoelectric and ferroelectric properties of the lead-free [[([K.sub.0.458][Na.sub.0.542]).sub.0.96][Li.sub.0.04]]Nb[O.sub.3] ceramics are examined. The X-ray diffraction results have shown that the phase structure has undergone a transition from orthorhombic to tetragonal phase.

The out-of-plane and in-plane x-ray diffractions are employed to explain the structural, as well as the dielectric characterizations of the relaxor/ferroelectric superlattice films Pb([Sc.sub.1/2][Nb.sub.1/2])[O.sub.3]/PbTi[O.sub.3], which are fabricated on a single-lattice scale. The superlattice structures of the films are shown to be coherent over the entire sample.

A qualitative study of the dynamics of the domain wall movement in pure and doped Pb([Zr.sub.1-x][Ti.sub.x])[O.sub.3] ceramics with different compositions is presented. The results show that the relative increase of the domain walls mobility in donor-doped materials is greater than the decrease in acceptor-doped materials due to the pinning produced by complex defects.

The studies about the microstructural and electrical properties of lead fluoroborate glasses which are dependent on the Pb[F.sub.2] glass content is reported. The findings can be applied to monitor the crystallization in glassy material and study dielectrical relaxation processes of materials viewed simultaneously from both time and frequency domains.

The fabrication and characterization of lead titanate nanoislands on platinized silicon substrates embedded into a low-k dielectric are described. The direct electrical characterization of sub-100-nm ferroelectric nanoislands is feasible if they are measured in parallel, providing that the thin film material parameters of both ferroelectric and spin-on glass are independently determined.

Bilayered mutliferroic nanocomposite films of preferentially oriented Pb([Zr.sub.0.52][Ti.sub.0.48])[O.sub.3] (PZT) and Co[Fe.sub.2][O.sub.4] (CFO) are prepared on general Pt/Ti/Si[O.sub.2]/Si substrate by using a simple solution processing. Strong ferroelectric and ferromagnetic responses and direct magnetoelectric coupling effect are observed in these bilayered thin films at room temperature.

Bilayered ferroelectric thin films consisting of Pb([Zr.sub.0.52][Ti.sub.0.48])[O.sub.3] (PZT) and ([Bi.sub.3.15][Nd.sub.0.85])[Ti.sub.3][O.sub.12] (BNT) layers are fabricated by using sol-gel and radiofrequency (rf) sputtering methods. The BNT/PZT bilayered thin films have shown better ferroelectric behavior than that of the PZT/BNT film where the P-E hysteresis loop is well saturated with higher polarization and they have shown much improvement in fatigue behavior when compared to that of the single layer PZT film.

BiFe[O.sub.3] and PbTi[O.sub.3] are used on a Sc-modified Pb([Fe.sub.2/3][W.sub.1/3])[O.sub.3] compound with strong cation order in order to enhance the multiferroic properties. BiFe[O.sub.3] is selected due to its multiferroism and large ferroelectric remanent polarization and PbTi[O.sub.3] is selected due to its high ferroelectric transition temperature and its ability to stabilize the perovskite phase.

The scaling of the polarization and the static dielectric susceptibility is by using a mean-polarization approach for ultrathin epitaxial Pb[Zr.sub.x][Ti.sub.1-x][O.sub.3] thin films. The Curie temperature in ultrathin films is more sensitive to epitaxial strain when compared to the polarization and the critical thickness is dependent on the temperature-epitaxial strain parameter space.

The depolarization mechanisms under compressive stress in ferroelectric materials are described. The main thermodynamic driving force for domain switching is found to be due to only mechanical under compressive stress.

The growth, microstructure and electrical properties of epitaxial PbZr[O.sub.3] films of two different crystallographic orientations, grown on SrRu[O.sub.3]-covered (100)SrTi[O.sub.3] and on BaPb[O.sub.3]-covered and BaZr[O.sub.3]-buffered (100)SrTi[O.sub.3] single crystal substrates, respectively, are described. The studies have shown the antiferromagnetic behavior of the PZO films of both orientations.

Several analyses are conducted to examine the piezoelectric properties of the commonly used lead zirconate titanate (PZT) ceramics. The results confirm that the nanodomains present in these films highly respond to the electric field, unlike the microdomain.

The electron areal density and carrier mobility is modeled in a two-dimensional electron gas layer developed in a [delta]-doped AlInSb/InSb heterostrucutre. The dependencies of the electron areal density on temperature, spacer layer thickness, doping density and the quantum well thickness are calculated, as they have important implications for extraordinary magnetoresistance (EMR) sensor design.

The phase instability's role in understanding the piezoelectricity in systems like Pb(Zr, Ti)[O.sub.3] is examined. The results have shown that the phase instability, in contrast with polarization rotation, is responsible for the large piezoelectric properties of systems like Pb(Zr, Ti)[O.sub.3] in the vicinity of the morphotropic phase boundary.

A study was conducted to compute the intrinsic dielectric and piezoelectric properties of single domain, mechanically free, and surface charge compensated PbTi[O.sub.3] nanocrystals (n-Pt) with no depolarization fields, undergoing a finite size induced first order tetragonal->cubic ferrodistortive phase transition. The results showed an anomalous increase in piezocharge coefficients near approximately 15 nm, the critical size for n-Pt.

The nonlinear dielectric properties of 0.9Pb([Mg.sub.1/3], [Nb.sub.2/3])[O.sub.3].0.1PbTi[O.sub.3] (PMN-PT) and Ba[[Ti.sub.0.85], [Sn.sub.0.15]][O.sub.3] (BTS) paraelectrics are investigated. The results have shown that the nonlinear dielectric properties of PMN-PT are higher than that of BTS.

The effects of hydrostatic pressure and biasing dc electric field on the relaxor response of samples of Pb{[Mg.sub.1/3][Ta.sub.2/3]}0.95Zr0.05[O.sub.3] with 12%, 15% and 90% B-site cationic order were investigated. A high temperature dielectric relaxation with an activation energy of 1.27 eV is observed for the 90% ordered sample, but not for 12% and 15% ordered samples.

The refractive indices, birefringence, and linear electro-optic (EO) effect of 0.62Pb([Mg.sub.1/3][Nb.sub.2/3])[O.sub.3]-0.38PbTi[O.sub.3] (PMN-PT) single crystals are characterized as a function of wavelength. The two-term Sellmeier dispersion model, in which one oscillator frequency is polarization dependent, is used to discuss the dispersion properties.

The crystal structure, electrical and optical properties are investigated for the lanthanum-modified lead zirconate titanate (PLZT) films prepared by radio-frequency (rf) magnetron sputtering. The results have shown that the PLZT ferroelectric thin films are promising materials for optoelectronic devices.

An experiment is conducted to study the fatigue properties of monolithic piezoelectric Pb([Mg.sub.1/3],[Nb.sub.2/3])[O.sub.3]-PbTi[O.sub.3] bilayer composites and study them as functions of piezoelectric-electrostrictive volume fraction (PEVF) ratio. The results thus obtained clearly reveal that the electrostrictive layer highly enhances the fatigue resistance and induce residual stresses in such layers, leading to the partial switching of the domains.

A conventional ceramic processing is used for the preparation of multiferroic laminated composites of Pb[Zr.sub.0.52][Ti.sub.0.48][O.sub.3]/Co[Fe.sub.2][O.sub.4], which is further observed to investigate its dielectric, magnetic and magnetoelectric properties. The analysis reveals that the nature of the PZT and cobalt ferrite (CFO) layers highly influence the properties of such ceramics, which can also be estimated by using the finite-element method.

A study is conducted to observe and compare the properties of lead zirconate titanate (PZT) thin films when they are doped with certain materials like barium, manganese, or fluorine-manganese codoped, to increase and improve their piezoelectric activities. The research reveals that the use of such doping materials can increase the hardness and other properties of the films, which then become very much suitable to be used in various microelectronic and microelectrochemical system applications.

The complex dielectric permittivity studies of the [001]-oriented Pb(Mg1/3Nb2/3)O3 (PMN)-x% PT single crystal with the MPB composition is conducted as a function of temperature and poling field along [001]. The dielectric permittivity of the unpoled crystal exhibited two phase transition anomalies at [T.sub.T-R]~355 K and [T.sub.C-T]~424 K.

Lateral size effects of ferroelastic domain structures in epitaxial PbTiO3 thin films are investigated systematically with a viewpoint of misfit strain relaxation mechanism. The results manifest that the domain structure and evolution of the epitaxial thin films could be engineered by the control of misfit strain and its relaxation.

A powerful analytical model for a multilayer circular plate, taking into account the tensile/compressive initial stress of materials, is developed. This model is modified for the study of the piezoelectric constant [d.sub.31] of PZT 54/46 thin film integrated on microscaled circular buckled membranes.

A relaxor-to-normal, or micro-to-macrodomain, transition in Pb([Mg.sub.1/3][Nb.sub.2/3][O.sub.3])-xPbTi[O.sub.3], is found under electric fields applied along [001] for x>=0.24. The results have shown that an intermediate tetragonal ferroelectric phase is important to the sharpness of this transition, as observed in its dielectric response.

The effect of the nanostructure on the electrical conductivity of n-type In-doped PbTe thin films was studied. The results reveal that in the nanostructured n-type films with the high density of grain boundaries, thermally activated hole conductivity becomes dominant and leads to its inversion from n to p type.

A demonstration that the position of the morphotropic phase boundary (MPB) and transition temperature at MPB in ferrolectric perovskite solutions could be predicted with quantitative accuracy from the properties of the constituent cations is presented. Results reveal that the mole fraction of PbTiO3 at MPB in Pb(B'B'')O3-PbTiO3, BiBO3-PbTiO3, and Bi(B'B'')O3-PbTiO3 exhibits a linear dependence on the ionic size and the ionic displacements of the B cations as found by density-functional-theory calculations.