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The electrochemical and dielectric responses were examined in transverse and longitudinal modes for relaxor ferroelectric solid solution Pb([Mg.sub.1/3][Nb.sub.2/3])[O.sub.3]-PbTi[O.sub.3] (PMNT) near a morphotropic phase boundary composition. The results highlighted the change in relative permittivity with pressure-induced suppression of electromechanical response, corresponding to electromechanical coupling coefficient (k).

The temperature and frequency dependent dielectric study of PbS and PbS:Mn nanorods of diameter approximately 30 nm grown in polymer matrix are reported. The results provide insights into the low frequency divergence of dielectric constant and tunneling of carriers, a dominant mechanism of carrier transport and the dielectric behavior of nanorods, which are influenced by Mn doping centers within PbS lattice.

An extensive study was conducted to examine the effects of different annealing temperatures on the film texture and the electric polarization properties of Pb[Zr.sub.0.53][Ti.sub.0.47][O.sub.3] (PZT) films grown by sol-gel synthesis. The findings suggested that the PZT domains self-organize into flower-like dendritic structures with a 'rosetta' shape at the early state of crystallization, at annealing temperatures higher than 600 degree Celsius.

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.

Incomplete cuboidal clusters when reacted with group 14 and 15 metal complexes with [s.sup.2][p.sup.0] electronic configuration resulted in the formation of heterometal incorporated cuboidal clusters. X-ray diffraction studies showed the cuboidal clusters as weak complexes of the cluster tridentate ligand with [EX.sub.3].

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.

Hydrogen transfer from Si-, Ge-, Sn-, and Pb-substituted methane and isobutene to methyl and t-butyl radical sites is investigated. The importance of using small-core pseudo-potentials in obtaining accurate barriers and reaction energies is demonstrated.

Switching current measurements are carried out on a soft lead zirconate titanate and the experiments have showed a single switching current peak during the application of electric field to a nonpoled sample. A single pyropeak is seen in the forward poles case and broadened peak is seen in case of a reverse poled sample.

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.

The impact of chemical ordering on the dielectric properties of the thin film relaxor lead scandium tantalate (PST) is examined. The impact of the defects and the quantitative reduction of the area of true relaxor regions are responsible for low permittivity thin film relaxors, which possess similar features to ceramic relaxor behavior.

The effects of the lead niobate (PZN) addition and postannealing temperature on the electrical properties of the lead zirconate titanate (PZT) films are examined in order to improve the electrical properties of the PZT film. The PZN-added PZT film has displayed poorer electrical properties than the pure PZT film when the films are coated on the silicon substrate and annealed at 700 degree Celsius.

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 phase transition from amorphous to face-centered-cubic (fcc) polycrystalline [Ge.sub.2][Sb.sub.2][Te.sub.5] thin films is studied. The results have presented a key ingredient for tailoring the kinetic of crystallization of the chalcogenide alloys and a general aspect of the phase change mechanisms in materials with high disorder level.

The phase transition via an intermediate state in lead-zirconate-titanate-based (PZT) solid solutions as well as the behavior of the piezoelectric properties of these solid solutions in the process of such a transition is examined. The results have shown that within the interval of existence of the intermediate state the piezoelectric material parameters are controlled by an applied electric field.

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.

The constant phase element (CPE) modeling is used to show that low-field electrical characteristics of the submicron lead zirconate-titanate (PZT) capacitors have exhibited specific frequency dependence. Despite problems with the microscopic origin of the CPE parameters, this approach is much better than the fixed frequency measurements of effective capacitance.

Diffraction intensities are measured in situ during dynamic electric field cycling of a soft, tetragonal polycrystalline lead zirconate titanate (PZT) ceramic by using stroboscopic neutron diffraction. The intrinsic lattice strain estimate and the extrinsic non-180[degree] domain switching calculations have agreed with the measured macroscopic strain.

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.

A new heterometallic iodometallate containing Pb and Cu, [[Co[(phen).sub.3]].sub.2][[Pb.sub.3][Cu.sub.6][I.sub.16].[C.sub.2][H.sub.5]OH, is synthesized that displays a novel [Pb.sub.3][I.sub.6][I.sub.16] net structure. The clusters form a BN-type layer, where [Pb.sub.3][I.sub.11] and [Cu.sub.6][I.sub.11] clusters take the place of B and N, and the layers contain cavities in which ethanol molecules are located.

The effects of the Zr-content on the structural, electrical and electromechanical properties of Pb[[Zr.sub(x)]][Ti.sub.(1-x)][O.sub.3] [PZT(x/1-x)] thin films are examined in detail. It is seen that the rise in Zr content increases the unit cell size and forces the preferred phase to become rhombohedral above the morphotropic phase boundary (MPB) while the increased unit cell size changes the switching behavior and increases the intrinsic behavior of the unit cells.

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.

A new, simple, organometallic synthetic technique is described for the preparation of Cu, Pb, or both (co-)doped ZnS nanocrystals without injection of precursors. The technique can be further exploited for the synthesis of other doped, sulfide-based semiconductor materials.

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 analysis of epitaxial growth of SBN50 ([Sr.sub.0.5][Ba.sub.0.5][Nb.sub.2][O.sub.6]) thin films on SrTi[O.sub.3] single crystal of various orientations is described. The findings revealed an interesting nucleation mechanism of SBN films, the perovskite kernel of the tetragonal tungsten bronze (TTB) structure nucleates first and determines the expitaxial relations with the substrate.

Control of cationic conjugated polymers (CPs) performance in light emitting diodes by choice of counterion was studied. It was found that the performance of CPs as the electron transport layer (ETL) in polymer lead emitting diodes is strongly influenced by the charge compensating ions.

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.

A study fabricated the polycrystalline nanosize (~60 nm) of (1-x)Pb(Fe2/3W1/3)O3-x(BiFeO3) solid solutions with a wide range of concentrations using a mechanical activation followed by a conventional solid-state reaction technique. Detailed dielectric studies of sintered pellets reveal that relaxor properties in Pb(Fe2/3W1/3)O3 (PFW) is induced with 10% addition of BiFeO3 (BFO) in (1-x)Pb(Fe2/3W1/3)O3+x(BiFeO3) (PBFW) solid solution.

Domain switching process in hyper-[T.sub.C] poled lead titanate zirconate (PZT) ceramics under two types of orthogonal electromechanical loading, axial electric cycling coupled with lateral compression and axial compression coupled with lateral electric cycling is studied through D-E hysteresis loops and stain measurements. Results reveal that along the original poling direction, the D-E hysteresis loops, the butterfly loops, and reversed butterfly loops are all nonsymmetric due to the existence of internal bias field by aging after poling.

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.

Sols for Pb(Zr0.53Ti0.47)O3 (PZT) thin films were prepared by 2-methoxyethanol route from lead acetate, titanium n-propoxide, and zirconium n-propoxide, the latter either unmodified or modified with acetylacetone or acetic acid in a 2/1 molar ratio and deposited on sapphire (0001). The modification of Zr propoxide with acetylacetone in 2-methoxyethanol results in Zr monomers.

Capacitor over bit line (COB) cell technologies are introduced upon which cell size of 0.937 mu [m.sup.2] at 250 nm minimum feature size technology node is realized based upon ultrathin lead zirconium titanate (PZT) capacitor, current mass-productive one pass transistor and one storage capacitor (ITIC). The new ITIC, COB cell technologies are discussed from which cell size of 0.27 mu [m.sup.2] at 150 nm minimum feature size technology node is realized.

A thermodynamic theory is developed for equilibrium 180 degree stripe domains in ferroelectric thin films on insulating substrates. Such stripe domains form to minimize the energy of the depolarizing field, and lead to a suppression of [T.sub.C] in thin films.

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.

The characterization of PbS colloidal quantum dots has helped in determining the diameter and the shape of the nanocrystals. The extinction coefficients as well as the absorption cross sections for a size series of PbS nanocrystals dispersed in hexane are found to be strongly dependent on the particle size.

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 deposition and ferroelectric properties of thin films of Pt/Ti/Si[O.sub.2]/Si (PST) with x = 0.3, 0.4, 0.5 and 0.6 and its graded composition are described by using sol-gel technique. The graded thin films have displayed a diffused phase transition accompanied by a diffused peak in the temperature variations of dielectric constants, which can be used in the fabrication of a temperature stable tunable device.

Nanosized PbS is fabricated on the Ti[O.sub.2] films and the components of the modified Ti[O.sub.2] films are studied by X-ray diffraction (XRD) and electron probe microanalysis (EPMA). The results have shown that the surface modification with optimum nanosized PbS on Ti[O.sub.2] leads to a performance improvement effectively.

Temperature and orientation dependence of dielectric and piezoelectric properties in poled Pb([Mg.sub.1/3][Nb.sub.2/3])[O.sub.3]-PbTi[O.sub.3] crystals were investigated. The results reveal that the domain configurations and phase transitions in the poled crystals strongly depend on both composition and orientation.