Materials Literature
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A longstanding goal of research in semiconductor spintronics is the ability to inject, modulate, and detect electron spin in a single device. A simple prototype consists of a lateral semiconductor channel with two ferromagnetic contacts, one of which serves as a source of spin-polarized electrons and the other as a de…
The resistive and reactive parts of the magneto-impedance of sintered ferromagnetic samples of La0.7Sr0.3-xAgxMnO3 (x = 0.05, 0.25) have been measured at room temperature (
The problem of the partial discharge (PD) extinction is investigated. The transient process takes place in a small spherical inclusion which is located in the dielectric. Both the losses caused by polarization and ohmic losses as the dielectric parameters are taken into account. From the inclusion standpoint the diele…
Previous attempts to refine the crystal structure of welshite, known only from Långban, Sweden, have been foiled by its extensive polysynthetic twinning, and without a structure determination, derivation of a reasonable formula has been difficult due its eclectic chemical composition. We report a successful refinement…
Etheral solutions of free base tripyrrins (HTrpy) were prepared by treatment of nickel isocyanate complexes (TrpyNiNCO) with excess cyanide. From these solutions sensitive metallotripyrrins with cobalt(II), iron(II), and manganese(II) ions (TrpyMX) and with a choice of external ligands X could be obtained in pure, cry…
El uso de interconectores metálicos en pilas de combustible de óxido sólido (SOFC) en sustitución de materiales cerámicos ha sido posible gracias a la investigación y desarrollo de nuevos materiales metálicos. Inicialmente, el uso de interconectores metálicos fue limitado, debido a la elevada temperatura de trabajo, o…
Polyhydroxyalkanoates (PHAs) are a class of biopolymers that are currently the subject of intensive research for various applications (packaging, consumer products, medical applications, etc.). It is known from synthetic polymers that all plastic materials show more or less pronounced autoxidation (aging induced by UV…
The 17 O NMR spectra of glasses quenched from melts at high pressure are often difficult to interpret due to overlapping peaks and lack of crystalline model compounds. High-pressure aluminosilicate glasses often contain significant amounts of [5] Al and [6] Al, thus these high-pressure glasses must contain oxygen bond…
Experiments in the system K 2 O-(NH 4 ) 2 O-Al 2 O 3 -SiO 2 -H 2 O-HCl have been conducted between temperatures of 400 and 600 °C at pressures of 200, 400, 500, and 1500 MPa. The run products consisted of solid solutions of the K-feldspar.-buddingtonite, muscovite- tobelite series, and quartz. The run products were ch…
The thermodynamic properties of crystalline and liquid KAlSi 3 O 8 are used to calculate the fusion curve of sanidine to 6.5 GPa. New values for the enthalpy and entropy of fusion of sanidine at one bar and 1200 °C (ΔH Tf = 63.0 kJ/mol, ΔS Tf = 42.8 J/mol-K) are recommended on the basis of improved heat-capacity equat…
Zincalstibite, a new mineral occurring within the cavities of marble of the Apuan Alps, Tuscany, Italy, has chemical formula Zn 2 AlSb(OH) 12 , space group P3̄, a = 5.321(1), c = 9.786(2) Å. It is associated with sub-millimeter tufts of white crystals of mimetite and sub-millimetric stalactite aggregates of opal and a…
The crystal structure of tooeleite, Fe 6 (AsO 3 ) 4 (SO 4 )(OH) 4 ·4H 2 O, has been solved from high-resolution synchrotron XRD powder data recorded on a sample from Tooele county, Utah. The structure is monoclinic, space group C2/m, a = 8.9575(1), b = 6.4238(1), c = 9.7912(1) Å, β = 96.032(1)°, V = 560.27(3) Å 3 , d…
Spinel single crystals of four compositions along the MgAl 2 O 4 -MgMn 2 O 4 join, with Mn 3+ up to 0.25 apfu, were synthesized by use of a flux-growth method. The crystals were analyzed by electron microprobe, X-ray single-crystal diffraction, and optical absorption spectroscopy. Results revealed that Mg contents var…
The graft copolymerization of 2-hydroxyethylmethacrylate (HEMA) onto poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) films has been investigated. The graft copolymerization was conducted in aqueous media using benzoyl peroxide (BPO) as chemical initiator. PHBHV films were prepared by solvent casting. Different pa…
In this work, we present a facile route to fabricate three-dimensionally ordered macroporous SiO 2 /graphitized carbon, TiO 2 /graphitized carbon, and the resultant graphitic carbon. The graphitized carbons were formed by catalytic graphitization of polystyrene arrays, which were used as both template and carbon sourc…
A novel noncovalent approach is developed for the functionalization of multiwalled carbon nanotubes (MWNTs) using a biopolymer obtained in the cellulose industry sodium lignosulfonate (SLS). Using a simple physical grinding technique, the SLS-functionalized MWNTs can be well-dispersed in water with a MWNTs-equivalent…
In-situ X-ray absorption spectroscopy at the Fe K-edge was used to characterize the local structural environment of Fe 2+ and Fe 3+ in silicate melts at high temperature (up to 1050 °C) in comparison to their quenched glassy analog at room temperature. Measurements were performed on binary alkali-silicate compositions…
Single crystals of a semi-organic nonlinear optical (NLO) material, l -proline cadmium chloride monohydrate ( l -PCCM), were grown by the slow evaporation and slow cooling method. The synthesized material was purified by repeated recrystallization. The grown crystals were transparent and had dimensions 16 × 8 × 5 mm 3…
Electrochemical etching of semiconductors, beside technical applications, provides an interesting experimental setup for self-organized structure formation capable of regular, diameter-modulated, and branching pores. The underlying dynamical processes governing current transfer and structure formation are described by…
Rietveld refinements using synchrotron powder X-ray diffraction data were used to study the crystal structure and dehydration behavior of sepiolite from Durango, Mexico. The room-temperature (RT) sepiolite structure in air compares well with previous models but reveals an additional zeolitic H 2 O site. The RT structu…