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Series: De Gruyter STEM
Reliability and Sustainability
Series: De Gruyter STEM
From Mountain Bikes to Degradable Bone Grafts
Series: De Gruyter STEM
Series: De Gruyter STEM

Abstract

The development of transparent conducting oxide materials has gained an increased interest in the scientific community for developing efficient low cost optoelectronic devices. The effect of Cd precursor on structural and optical properties of sol-gel synthesized Zn0.9Cd0.1O nanostructured films has been studied by using XRD, AFM, optical absorption and emission spectroscopic techniques. X-ray diffraction confirms the hexagonal wurtzite crystal structure of the deposited films and the relative intensity of diffraction peaks has been observed with different cadmium salts. The granular surface morphology of the synthesized films has been observed from AFM measurements. The optical transmission, band gap and luminescence intensity was found to change for different cadmium salts. These results are very important for developing new materials for optoelectronic applications.

Abstract

Ceramic lead niobates and their solid solutions (1 – x)Pb(Sc0:5Nb0:5)O3 – xPb(Yb0:5Nb0:5)O3 were synthesized by solid state reactions from oxides. The structure of investigated samples was characterized by X-ray diffraction (XRD). Dielectric studies of the ceramics were performed by means of broadband dielectric spectroscopy at the temperature ranging from 600 K to 140 K. For all ceramic samples a diffuse phase transition as well as relaxor ferroelectric behavior were observed.

Abstract

The improved TiB2 ceramics were obtained in sintering process at the pressure of 5.5 GPa and temperature of 1550 °C in presence of metallic Co powder. The effect of Co content (ranging from 0 wt.% to 10.0 wt.%) on the phase composition, density, microstructure, Vickers hardness and thermal conductivity of TiB2 ceramics was analyzed. A small amount of new phase Co2B has been created in the reaction of TiB2 and Co. The relative density of sintered TiB2 ceramics reached 98.1 %. When the mass fraction of Co increased, the porosity increased, while the hardness first increased and then decreased. The maximal Vickers hardness values were equal to 33.3 GPa or 28.2 GPa when the used load was of 4.9 N or 9.8 N, respectively. The highest reached value of thermal conductivity was 88.9 W˙m−1 ˙K−1. The dense TiB2 ceramics with improved hardness and thermal conductivity were ascribed to the high pressure sintering method and Co sintering aid. High pressure sintering method provides a new way for the preparation of ceramics materials.

Abstract

This article discusses the growth and characterization of (((4-sulfonatophenyl) ammonio)oxy) zirconium (SAOZ) single crystals. Sulphanilic acid incorporated zirconium oxychloride semi-organic single crystals have been synthesized by slow evaporation technique. From the X-ray studies, lattice parameters a = 7.31 Å, b = 7.51 Å, c = 13.92 Å, volume = 765 Å3 have been found and so the crystal has been identified as orthorhombic with non-centrosymmetric space group P212121. The powder XRD examination demonstrated the quality and high crystalline nature of the grown crystal. The presence of functional groups was confirmed by FT-IR technique. The chemical structure of the compound was established by 1H and 13C NMR spectra. The optical transmittance window and the low cutoff wavelength of SAOZ have been identified by UV-Vis-NIR studies. Photoluminescence studies showed a wide blue light emission. TG and DTA examinations were carried out to characterize the thermal behavior of the grown crystal. The mechanical strength of the grown crystal was analyzed by the Vickers microhardness test. The elemental analysis was done by EDAX. The dielectric response of the crystals was analyzed in the frequency range of 50 Hz to 5 MHz at various temperatures and the outcomes were discussed. The SHG efficiency was estimated in correlation with KDP by employing powder Kurtz method.