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The necessity of developing technologies based on the use of solar energy as an energy-saving renewable natural resource is shown. Ceramic materials were obtained in a Large solar furnace (Parkent) with a capacity of 1000 kW: aluminum titanate, corundum, solid solutions based on ZrO2, Bi/Pb-superconducting material and the influence of the conditions for obtaining these materials on the microstructure, unit cell parameters, strength was established. The possibility of the development and practical application of concentrated solar energy for ceramic materials production is shown. Ill. 3. Ref. 25. Tab. 1.

Using a highly sensitive torsional vibration technique, the authors have determined the critical temperatures of the superconducting transition (Tc) of individual phases of multiphase cuprates [Bi1.7Pb0.3Sr2Ca(n-1)CunOy (n = 2–30)] in a constant external magnetic field (H) in the temperature range of 77 to 270 K. It has been found that oscillation damping peaks are more pronounced when a sample is rapidly cooled in an external magnetic field (FC) to a temperature of 77 K and then is slowly warmed to room temperature. An increase in the time of sample exposure to a magnetic field at 77 K leads to a rise in the temperature Tc of different phases, and to an increase in the intensity of a signal corresponding to high-temperature phases with Tc > 240 K. Structural studies have shown that with increasing sample exposure time at 77 K, as a result of sample compression an increase in stress concentration at grain boundaries appears to increase defect density and to enhance the pinning of Abrikosov vortices, i.e. creates new (additional) conditions for their “freezing” during the field cooling (FC) procedure. It has been established that in samples of the Bi1.7Pb0.3Sr2Ca(n-1)CunOy (n = 2–30) series, the critical temperature Tc increases from 107 K to ≥ 240 K with an increase in n.

The electrophysical properties of semiconductor–superconductor sandwich pairs (InP–Bi/Pb 2223, 2234, 2245) are investigated, in which homophase superconductors based on bismuth cuprates with high reproducible critical temperatures of superconducting transition Tc = 107–180 K are used. The advantage of melt solar technology for obtaining superconducting materials is demonstrated. The microstructure and phase composition of strongly anisotropic superconductors with nominal composition Bi1.7Pb0.3Sr2Ca(n– 1)CunOy (n = 3, 4, 5) are researched. A technique of experimental determination of superconducting transition critical temperatures Tc in single-phase and homophase HTSC samples is presented. The current–voltage characteristics of InP–Bi/Pb pairs are investigated. The relationship between the electrical resistance of sandwich pairs and superconductor critical temperature Tc is established.

An opportunity of using solar energy to develop a multicomponent ceramic material synthesis technology using melts has been demonstrated. Optical and energy parameters of the 1 MW Large solar furnace for synthesizing aluminum titanate-based materials are presented along with their phase and grain size compositions depending on the melt cooling rate. A possibility of obtaining a two-phase material containing the tialite phase and spinel is shown. A positive effect of the spinel phase on the properties of ceramics made from the material synthesized by using solar energy has been established.

The advantages of the melt technique for the synthesis of superconducting materials are shown in comparison with the solid phase technique. Glass crystal precursors of the Bi1.7Pb0.3Sr2Ca(n – 1)CunOy series (n = 2–20) synthesized with SFAQ-T (Super Fast Alloys Quenching) technology under the influence of concentrated solar energy are used to produce superconducting Bi/Pb phases with increased superconducting transition temperatures.

In this study, the potential possibilities of the precision of the vibrating reed method for the evaluation of the . of superconducting precursors in an HTSC Bi-Pb-Sr-Cu-O system were investigated. A special technology for obtaining these samples by using solar energy for melting and following superfast melt quenching was applied to increase their internal inhomogeneity, allowing to receive high-quality textural ceramic samples of Bi1,7Pb0,3Sr2Can-1CunOy (n=2-30) showing critical temperatures of superconducting precursor transitions above bulk Tc. To determine critical temperatures of superconducting precursors above bulk Tc for the first time, the original vibrating reed method of studying these multiphase samples in an applied magnetic field was used. It was shown that this method has sensitivity to superconducting diamagnetism making possible to reveal new superconducting precursor phases above bulk Tc.

The phase composition and superconducting properties of high-temperature superconductors of homologous series of Bi1.7Pb0.3Sr2Ca n − 1Cu n O y (n = 4−9) based on amorphous precursors obtained under the influence of solar energy was studied. The formation of structural defects was established, and their relation with the increase in the temperature of the superconducting transition up to 181 K was assumed.

The problem of energy shortage governs the search for renewable energy sources. Solar energy is used to synthesize and study the properties of the following oxide compounds: REE titanates (La–Lu), titanates of the pseudo-brookite type, solid solutions of the fluorite type based on ZrO2 and HfO2, and superconductors of theseries Bi1.7Pb0.3Sr2Ca n–1Cu n O y (n = 2 – 20). The advantages of synthesis technology using solar energy and a favorable change in ceramic functional material properties is demonstrated.

The phase composition of composite ceramic based on aluminum titanate and additives synthesized by concentrated solar radiation by means of solid phase reactions and by the induction method is investigated. It is revealed that the additives positively influence the sample’s mechanical properties.

The mechanical properties of an aluminum titanate-based ceramic are increased by decreasing the grain growth kinetic of the initial material, which is synthesized by melting in a solar furnace. The thermomechanical properties are improved if the following additives are introduced: mullite, spinel, and a eutectic of Al2O3-ZrO2.

The possibility of obtaining superconducting phases in compositions Bi1.7Pb0.3Sr2Cax − 1CuxOy (x = 4, 5, 7, 9) with increased Ca and Cu content from amorphous precursors that are obtained under the action of concentrated sunlight is investigated. It is established that the temperature of formation of the superconducting phases decreases with increase of the Ca and Cu content.

Investigated is the possibility of synthesis of cubic silicon carbide from silica earth minerals (quartzite and quartz sand) by exposure to intense solar radiation. The influence of the intensity of the solar radiation flux on the silicon carbide formation process is studied in detail.

cited By 1; International audience; Production of superconducting ceramics based on precursors with rated composition Bi1.7Pb0.3Sr2Ca2Cu 3O y is studied. The precursors are synthesized in a solar furnace by melt rapid quenching. The phase composition of the samples is examined by microstructural and X-ray analyses. The temperature dependences of the resistance and magnetic susceptibility are measured. The influence of the composition and crystal structure of the substrate on texturing in the Bi-Sr-Ca-Cu-O system is studied. It is found that the type of quenching plays a significant role, while the type of substrate is of minor significance. © 2009 Pleiades Publishing, Ltd.

The properties in isostructural and isostoichiometric series of monotitanates and dititanates of the rare earth elements (REE), titanates with structure of pseudobrookite type, and solid solutions with fluorite structure based on ZrO2 and HfO2 are investigated. The differences determined by molten phase synthesis via the action of concentrated solar radiation are shown. It is proposed that ozone and excited valence electrons, i.e., the factors caused by concentrated solar radiation, influence the phase composition and properties of these oxide compounds.

The investigation of temperature dependence of damping and period of vibrations of HTSC superconductive cylinder of Bi-Pb-Sr-Ca-Cu-O system suspended by a thin elastic thread and performing axial-torsional vibrations in a magnetic field at temperatures above the critical one for the main phase Tc=107 K were carried out. It was observed some "chaos" temperature region in the temperature interval 107-138 K, where it is seen separate ripples of dissipation and oscillation frequency. It is assumed that the "chaos" region could point to a possibility of existence of other magnetic and more high-temperature phases as single islands in a normal materials matrix., Comment: 10 pages, 0 figures

The crystallization of the amorphous precursors BSCCO 2234, 2245, obtained by rapid quenching of a melt exposed to concentrated solar radiation, has been investigated. The formation of the 2223 and 2234 superconducting phases in the synthesis has been established.

The moldability and sinterability of the experimental chamotte specimens with the addition of Angrensk clay are examined. Data are presented on the deformation phenomena after sintering at 1150 to 1450°C. The thermal resistance and the strength of the specimens are studied, and also the effectiveness of the use of protective coatings with the addition of corundum that is obtained in the Big Solar Furnace. Conclusions are drawn on the possible use of these materials in the mixers of the glass smelting furnaces.

The possibility of synthesis of alumino magnesium silicate (MgO-Al2O3-SiO2) on a Big Solar Furnace is demonstrated. Thermomechanical properties of ceramics based on it are investigated. The obtained material has high mechanical and dielectric properties, and spark-resistant electrical insulating products can be produced from it.

A unit for integrated studies of mechanical properties and crystal structure of ceramics under different conditions is considered.

The properties of the spherulites based on aluminum oxide, mullite, and zirconium dioxide that are obtained by melting and subsequent quenching in a 1000 kW solar furnace are studied. These spherulites are hollow. The thickness of the wall of the sphere is determined by the quenching rate. The microstructure of the spherulites that are based on aluminum oxide consists of crystallites of cubic form, the microstructure of the spherulites that are based on zirconium dioxide consists of micrograins of rounded form. The hardness and the elastic properties exceed the known values for the electrically melted materials that are based on corundum and zirconium dioxide.

The possibility of obtaining basalt fiber based on mineral raw material from Uzbekistan using heating by concentrated solar radiation is investigated. The phase composition and properties of the basalt fiber obtained by a conventional technology using gas and solar energy as an energy carrier are studied. The parameters of the solar furnace in the technological process of obtaining basalt fiber are determined. The first results attest that concentrated solar energy can be used to produce ‘green’ technologies for obtaining fibrous materials.

We studied the influence of the form and amount of stabilizer and the synthesis schedules on the phase ratios in the approximate eutectic compositions for the systems ZrO2-Al2O3 (MgAl2O4, SiO2, mullite), and also the thermodynamic stability and mechanical properties of the ceramics based on them.

En vue de mieux comprendre les effets de la microstructure, on etudie l'influence de la grosseur de grain et de la disposition relative des grains sur la stabilite thermodynamique de ceramiques de titanate d'aluminium.

The possibility of obtaining basalt mineral fibers using concentrating solar power and melt-quench technique is shown. The microstructure and physicochemical properties of basalt fibers are analyzed.