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In this work, were synthesized (Pb0.91La0.09)(Zr0.65Ti0.35)0.9775O3 ceramic materials with different concentrations of praseodymium (0, 0.1, 0.3, 0.5, 1 wt.%) via gel-combustion route and sintered by the hot uniaxial pressing method. Measurements were conducted on the obtained ceramics using X-ray powder diffraction (XRD), scanning electron microscope (SEM), EDS analysis, and examination of dielectric and ferroelectric optical properties. Results give us a detailed account of the influences of the praseodymium ions on the structural, microstructural, and dielectric properties. 3D fluorescence maps and excitation and emission spectra measurements show how a small admixture changes the ferroelectric relaxor behavior to an optically active ferroelectric luminophore. [ABSTRACT FROM AUTHOR]

In the presented work, the tellurite glasses TeO2-WO3-ZnO doped with Tm3+ and Ho3+ ions were prepared by the same glass forming method. X-ray diffraction (XRD) and differential thermal analysis (DTA) techniques were used to study the effects of the forming technology on the thermal and structural properties of the fabricated glasses. After controlled crystallization of investigated glasses, the emission in the VIS- and NIR range was determined. The effect of silver doping on emission intensity was investigated. The value of the activation energy of the glass crystallization process was determined, while the Ea value for pure TeO2 glass was much lower than for tellurite glasses TeO2-WO3-ZnO. [ABSTRACT FROM AUTHOR]

The RF shielding effect SD was measured in a YBCO bulk cylinder and constant values in frequency range from 1 MHz to 10 MHz were exhibited.

Abstract: This work reports on the phase formation during a solid-state reaction of Eu3+-doped garnets with the general formula A3B2Ge3O12 (A=Ca, Sr and B=Ga, In, Y) and their luminescent properties. It is shown by XRD and DTA/TG experiments that the garnet-phase formation is completed at 1100–1200°C. Moreover, it turned out that the position of the oxygen to europium charge-transfer band and the intensity of the forbidden 4f–4f transitions of Eu3+ is dependent on the covalent interaction between the Eu3+ activator and the surrounding oxygen anions. The investigated red-emitting luminescent materials show high lumen equivalents and deep red emission at the same time, which makes them attractive for the application in LEDs (light emitting diodes), in particular for near UV-emitting LEDs. [Copyright &y& Elsevier]

Abstract: In this study the densification behavior of LuAG:Nd (Lu3−x Nd x Al5O12) ceramics made by a combustion precursor was investigated. Precursor material synthesis was done according to a self combustion method and later calcined at different temperatures. Analysis of precursor materials was carried out by means of X-ray diffraction, TGA, dynamic light scattering and scanning electron microscopy. Green bodies were prepared by uniaxial and subsequently cold isostatic pressing. Green body densities were calculated by measurement of weight and dimensions. Ceramic bodies were sintered in a high temperature furnace for 4h at 1700°C in air atmosphere. Specimens were also analyzed by XRD and SEM. Additionally densities of specimens were determined using Archimedes method and the inline transmittance was measured at 1064nm. [Copyright &y& Elsevier]

This article presents a study of metamaterial structures that exhibit auxetic properties. This unusual phenomenon of simultaneous orthogonal expansion of the metamaterial in tension, and vice versa in compression, with vertical and horizontal contraction, is explored for structures made of re-entrant unit cells. The geometry of such structures is analysed in detail, and the relationships are determined by the value of the Poisson's ratio. It is shown that the Poisson's ratio depends not only on the geometry of the unit cell but also on the degree of strain. Depending on the dimensions of the structure's horizontal and inclined struts, the limit values are determined for the angle between them. By creating physical structures made of re-entrant cells, it is demonstrated that the mechanism of change in the structure's dimensions is not due to the hinging but to the bending of the struts. The experimental section contains the results of compression tests of a symmetrical structure and tensile tests of a flat mesh structure. In the case of the mesh structure, a modification of the re-entrant cells was used to create arched strut joints. This modification makes it possible to obtain greater elongation of the mesh structure and larger NPR values.