Bismuth oxide solubility in Bi2O3–ZnO–Nb2O5 and Bi2O3–MgO–Nb2O5 (BMN) pyrochlore systems was investigated and the solubility limits were identified. Differences in the solubility behavior between the two Bi-pyrochlore systems investigated were analyzed and explained through crystal chemistry concepts. For the BMN system, the dielectric constant was enhanced, and a systematic shift occurred in the dielectric relaxation loss peak to higher temperatures with increases in the excess bismuth are reported in the BMN system. The relationship between solubility and the shift in the dielectric loss curve was analyzed under the scope of possible relaxation mechanisms.

Na0.5K0.5NbO3 thin films have been deposited onto textured polycrystalline Pt80Ir20 substrates using radio frequency magnetron sputtering. Films were grown in off- and on-axis positions relative to the target at growth temperatures of 500–700 °C and sputtering pressures of 1–7 Pa. The deposited films were found to be textured, displaying a mixture of two orientations (001) and (101). Films grown on-axis showed a prefered (001) orientation, while the off-axis films had a (101) orientation. Scanning electron microscopy showed that the morphology of the films was dependent on the substrate position and sputtering pressure. The low-frequency (10 kHz) dielectric constants of the films were found to be in the range of approximately 490–590. Hydrostatic piezoelectric measurements showed that the films were piezoelectric in the as-deposited form with a constant up to 14.5 pC/N.

The dielectric behavior of manganese-doped morphotropic phase boundary (MPB) composition in the Pb(Zn1/3Nb2/3)O3–BaTiO3–PbTiO3 (PZN–BT–PT) system is described in this paper. Materials with perovskite structure were fabricated using the precursor approach. Addition of Mn stabilized the rhombohedral phase against the tetragonal one, moving the MPB territory toward the PbTiO3-rich side. Both the dielectric permittivity maximum (∈′m) and phase transition temperature (Tmax) were reduced by increasing Mn2+ content. Frequency-dispersion characteristics of Tmax were weakened while the frequency spectrum of the dielectric permittivity (∈′) was broadened, reflecting different underlying mechanisms. The broadness of paraelectric to ferroelectric phase transition was significantly enhanced by Mn-doping. This was associated with progressive increase in the degree of chemical heterogeneity on B-site cations. The observed proximity of the non-Curie–Weiss region to Tmax as well as shrinkage of this region for doped compositions suggest increased stability of the ferroelectric phase.

The effect of buffer and γ irradiation on the optical properties of hydroxyethyl methacrylate (HEMA) copolymer was investigated. The transmission of HEMA copolymer decreased with the increase of irradiation dose and/or pH value of the buffer. The cutoff wavelength of HEMA copolymer exhibits a bathochromic shift as the γ-ray dose and/or pH value of buffer increases. The influence of atmosphere during γ-ray irradiation on the optical properties of HEMA copolymer was investigated. The change of optical properties of HEMA copolymer irradiated in air was more pronounced than that irradiated in vacuum. Light was scattered by holes in the polymer. The relationship between scattering intensity (Is) and incident wavelength (λ) can be described by the formula Is ∝ λ−n. The span of holes increases with the irradiation dose regardless of radiation atmosphere and pH value in the range of 4.1–6.5. A boundary between the inner and outer layers of HEMA copolymer irradiated in air was observed, separating two differential morphologies of holes.

We report a new SBN-tellurite ceram-glass system, where the [(SrO)(y)(BaO)(1−y) (Nb2O5)](1−x) (SBN) ferroelectric crystallites precipitate on a tellurite (TeO2)x glass surface with nominal compositions x < 0.8 and y = 0.6 to 0.75. X-ray diffraction, calorimetry, and electro-optic measurements confirmed the ferroelectric nature of the SBN crystallites. In principle, this system has the potential for high transparency and the property tunability to match the application needs of optical devices.

The effective valence, of mobile cations (Fe2+, Fe3+) in semiconducting Fe3O4 was determined at elevated temperatures via Tubandt-type electrotransport experiments in association with the literature data on the cation diffusivity and total electrical conductivity. It has been found that the value for varies systematically from below 2 up to 3 with oxygen partial pressure at a fixed temperature. The effective valence is determined not only by the mobility difference of Fe2+ and Fe3+ ions but also by the cross effect between the cations and electrons upon their transfer . A value of between 2 and 3 may be attributed to the mobility difference between Fe2+ and Fe3+ ions even in the absence of the cross effect, but the values of < 2 clearly indicate that the cross effect is in play in Fe3O4.

CuO nanocrystals of three different sizes 3.5, 6.5, and 10.0 nm were synthesized by a novel electrochemical route. Quantum size effects in these nanocrystals are evident from the optical absorption spectra. The optical absorption feature is observed to be blue shifted by about 1 eV with size reduction. The CuO q-particles were found to be single-phased and very stable as far as the size and phase is concerned.

AlN/VN superlattices with different periods were studied using x-ray diffraction and transmission electron microscopy (TEM). A phase transformation of the AlN from an epitaxially stabilized rock-salt structure to a hexagonal wurtzite structure was observed for an AlN layer thickness greater than 4 nm. A structural model is proposed on the basis of TEM results for the orientation of the transformed phase. The VN layer grown on top of the hexagonal AlN was observed to be reoriented compared to that in the stabilized B1-AlN/VN. The VN nucleated by taking the w-AlN(002) plane as its (111) plane instead of the (002) plane.

The complex relative permittivity ∈γ and permeability μγ of microcoiled carbon fibers (MCCFs) imbedded in paraffin wax were measured at Ku band frequencies (12.4–18 GHz). Both the real and imaginary parts of the complex relative permittivity of the MCCFs/paraffin wax composite decreased with increase of the frequency. The real part of the complex relative permeability of the composite increases with increase of the frequency, and the imaginary part is nonzero and nearly constant over the measured frequency range. The dielectric loss tangent (tan δ∈), the magnetic loss tangent (tan δm), and amplitude attenuation factor (α) were determined as well. On the basis of the experimental results, the MCCFs/paraffin wax composite is mainly a kind of dielectric lossy material with small magnetic loss and diamagnetism in the Ku band.