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Piezoresponse force microscopy (PFM) is used for examining the domain structure of multiferroic BiFe[O.sub.3]-PbTi[O.sub.3] single crystals with morphotropic phase boundary (MPB) compositions. The analysis of the complex PFM patterns obtained from the design setup has disclosed the presence of the rhombohedral, tetragonal, and orthorhombic domains, which is characteristic of the phase behavior of the MPB compositions.

The typical characteristics of relaxor ferroelectric with broad and dispersive permittivity maxima are observed in the solid solution between the dielectric complex perovskite (BZN) and ferroelectric PbTi[O.sub.3] (PT).Findings reveal that the increase in PT content weakens relaxor behavior.

A study prepared bismuth-doped LaAlO3 in the form of solid solution, [La.sub.(1-x)][Bi.sub.x]AlO3, by solid-state reactions. It was observed that with increasing bismuth amount (x), the dielectric constant increases from 31.6 for pure LaAlO3 to 34.6 for x=0.2 while the loss tangent drops from 0.03 to 0.004.

High-pressure Brillouin and Raman scattering spectroscopy and x-ray diffraction measurements were performed on disordered Pb([Sc.sub.1/2][Nb.sub.1/2])[O.sub.3] to demonstrate its application as a model system for phase transitions in relaxor ferroelectrics and related materials. Both the temperature and pressure dependencies of the linewidth indicated that the longitudinal acoustic mode softening arises from electrostrictive coupling between polar nanoregions and acoustic modes.

The longitudinal acoustic phonon modes of Pb([Mg.sub.1/3][Nb.sub.2/3])[O.sub.3] (PMN) and La-doped PMN are examined by using Brillouin spectroscopy. The results have shown that the temperature evolution of dynamic polar nonregions and the related high-frequency dynamics of PMN-based crystals in the gigahertz range are not affected by the size of the B-site cation-ordered regions.

The synthesis and characterization of a new ferroelectric solid solution of (1-x)Ba([Yb.sub.1/2][Nb.sub.1/2])[O.sub.3]-xPbTi[O.sub.3] in the form of ceramics by solid-state reactions is reported. The system is observed to exhibit a morphotropic phase boundary with composition of 0.65

A new lead-free (1-x)BaTi[O.sub.3]-xBiAl[O.sub.3] solid solution is prepared by solid state reactions and the composition dependences of the structure and dielectric properties are analyzed. The studies have shown that the long-range polar order from the end member BaTi[O.sub.3] has persisted and coexisted with polar nanoregions induced by the chemical disorder following the coupled substitutions in the solid solution.

A new solid solution of (1-x)Ba([Zn.sub.1/3][Nb.sub.2/3])[O.sub.3]-xPbTi[O.sub.3] [(1-x)BZN-xPT] is synthesized in the form of ceramics by solid state reactions and characterized by using x-ray diffraction, dielectric spectroscopy and ferroelectric measurements. The room-temperature real permittivity of BZN-PT with morphotropic phase boundary (MPB) compositions is very high, indicating that the BZN-PT solid solution is useful in applications like microwave dielectrics and high power density capacitors.

The acoustic and dielectric properties of Pb[[(Zn1/3Nb2/3)].sub.1-x][Ti.sub.x]]O3 (PZN-xPT) single crystals with x=0.045 is conducted by the high-resolution micro-Brillouin scattering and dielectric spectroscopy in a wide temperature range. The softening of the Brillouin shift and the increase of dielectric relaxation time upon cooling indicated the formation of polar nanoregions (PNRs) and the slowing down of their dynamics.

The crystal structure, multinuclear solid-state NMR spectra and high optical birefringence of Pb[Au(CN)(sub 2)](sub 2)(H2O)(sub x) (x = 0, 1) are reported. The results show that Pb(H2O)[Au(CN)(sub 2)](sub 2) has high optical birefringence that is attributed to the anisotropy of the 2-dimensional slabs of 1, with all C triple bond N bonds aligned in the same direction by the polarization lead(II) center.