The study of the Na0.5Bi0.5TiO3–K0.5Bio0.5TiO3 (NBT‐KBT) system was carried out using X‐ray diffraction and dielectric measurements. The limits of rhombohedral and orthorhombic solid solutions were determined, as well as the evolution of their lattice parameters as a function of composition and temperature. Dielectric permittivity measurements in a wide frequency range between 20 and 800°C showed that all materials are ferroelectric at room temperature and exhibit a diffuse, probably second‐order phase transition from the ferroelectric to the paraelectric state. Several peculiar compositions showed the best piezoelectric characteristics for this type of ceramic materials.

The communication reports on the high performance of hydrogen-terminated silicon nanowires and silicon nanowires coated with metal (Ag, Cu) nanostructures for the photodegradation of rhodamine B under UV and visible light irradiation.

A study of the Na0.5Bi0.5TiO3-PbTiO3 and K0.5Bi0.5TiO3-PbTiO3 systems has been carried out using Xray diffraction, differential scanning calorimetry and dielectric measurements. The limits of the rhombohedral (Na0.5Bi0.5TiO3-rich side) and tetragonal (PbTiO3-rich side) solid solutions have been determined, as well as the evolution of their lattice parameters as a function of composition and temperature. Ceramic materials have been prepared by natural sintering (1090-1220 °C; 0.5 h) of powders obtained by solid-state reaction (900-1000°C; 20 h) of the corresponding oxides and carbonates. The dielectric permittivities of these materials have been measured in a wide frequency range for temperatures between 20 and 800 °C. The results showed that they all are ferroelectric at room temperature and exhibit either a diffuse, probably second-order phase transition, or a sharp, first order-like phase transition from the ferroelectric to the paraelectric state, depending on the composition.Lead titanate-zirconate ceramics (PZT) are currently the most used ferroelectric materials in the field of piezoelectric applications. A noticeable feature of these materials is the occurrence of a morphotropic phase boundary (MPB) in the phase diagram which separates tetragonal and rhombohedral ferroelectric regions. Solid solutions with compositions close to the MPB present the best electromechanical properties. In the research of new complex systems with interesting piezoelectric characteristics, care should be taken that thermal and time stability of the properties is connected with the value of the Curie temperature of the components. Previous works have shown that in most cases this corresponds to the situation where the MPB is located between tetragonal and rhombohedral phases. 1 Up to now, results concerning systems other than PZTs have only been devoted to either Na0.5Bi0.5TiO3-(Sr,Ba)TiO3 or the low-lead range of Na0.5Bi0.5TiO3-PbTiO3. [2][3][4][5][6] A study was therefore conducted on the whole Na0.5Bi0.5TiO3-PbTiO3 (NBT-PT) and K0.5Bi0.5TiO3-PbTiO3 (KBT-PT) systems, which are both likely to present MPBs. Actually, at room temperature NBT is rhombohedral (Tc  320 °C), KBT is tetragonal (Tc  380 °C) as is PT (Tc  490 °C). 7 This paper presents the results concerning the preparation of some materials belonging to this family as well as their thermal and dielectric properties.

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Abstracf -The study of the Nao.sBi0.sTiQ -K0.5Bio.sTi03, Na0.5Bio.sTi03 -PbTiOg and Ko.SBi0.STiOj -PbTi03 systems was carried out using X-ray diffraction, DSC and dielectric measurements. The limits of the rhombohedral (Nao.SBi0.sTiQ -rich side) and orthorhombic (Ko.5Bi0.5TiO3, and PbTi03-rich side) solid solutions were determined, as well as the evolutions of their lattice parameters as a function of composition.