Showing papers in "Materials Letters in 1988"

TL;DR: The fine particle nature of α-alumina and related oxide materials has been investigated using SEM, TEM, particle size analysis and surface area measurements in this article, where solid combustion products have been identified by their characteristic X-ray diffraction patterns.

TL;DR: In this paper, diamond microcrystallites and polycrystalline films were grown on various substrates in the ambient atmosphere with an oxygen-acetylene welding torch and analyzed with Raman spectroscopy, X-ray diffraction and electron microscopy.

TL;DR: In this article, the synthesis of nickel aluminides by mechanical alloying (MA) of mixtures of elemental nickel and aluminium powders has been reported and the major end product was disordered NiAl which was identified by X-ray diffraction and chemical analysis.

TL;DR: A phase belonging to the ternary system La2O3-Li2O-Me2O5 (Me=Nb, Ta) was prepared and characterized both chemically and structurally as mentioned in this paper.

TL;DR: In this paper, a hexagonal close packed nickel powder has been prepared upon reduction of Ni(II) with a K/B liquid alloy, which is stable at low temperature, undergoing a transition to a face centered cubic phase above 380°C.

TL;DR: In this paper, a method was developed to fabricate and quantify silica-based fibres doped with high concentrations of Nd3+ and Er3+ in an Al2O3-P2O5-SiO2 core glass.

TL;DR: In this article, the dielectric and electrical properties of Ba 1− x Sr 2+ on the Curie point of BaTiO 3 and the role of compositional inhomogeneity caused in the solid solutions on their electrical resistivity were investigated.

TL;DR: In this article, it was shown that high-temperature superconductors transform to a ferroelectric state prior to the onset of superconductivity, and several independent pieces of physical evidence lead to this conclusion.

TL;DR: Fractography of sintered nanophase and commercial coarser TiO 2 powders was carried out using scanning electron microscopy in this article, where the authors compared the fracture properties of the two powders and found that the nanophases had smaller voids and the sintering temperature for completely transgranular fracture was 200°C lower.

TL;DR: In this paper, the superconducting properties of YBa 2 Cu 3 O 7−x compacts above about 930°C were investigated and the highest current densities (≈ 500 A/cm 2 ) were obtained in these solid state sintered samples.

TL;DR: In this article, it was shown that changes in the corresponding optical absorption spectra result from quantum confinement effects, and these changes are related to particle size and allow growth and coarsening kinetics to be determined.

TL;DR: In this paper, the results of some experiments on the electromagnetic emission of heat-treated spring steel are reported and attributed to the abrupt deceleration of the accelerated energized dislocation during the creation of the new surfaces during the brittle fracture.

TL;DR: In this article, two new polymorphic erbium oxides have been found in small grains of nanophase ceramics by means of electron microscopy, one has a face-centered cubic (fcc) structure with lattice parameter a = 0.374 nm, the other has a monoclinic structure with a =0.359 nm, b = 0.,562 nm, c = 0,344 nm and β = 119.3°.

TL;DR: In this paper, the Ni-Zr system was analyzed with particular reference to diffusion couples and it was shown that there is no nucleation barrier for formation of the first phase, and why that phase is amorphous.

TL;DR: In this paper, a fine-grained eutectic microstructure in which the magnetically hard phase containing 20 at.% Nd is stabilized by oxygen and has a Curie temperature of 235°C was attributed to a fine grained eUTectic structure.

TL;DR: In this paper, a low pressure vapor phase epitaxy (LPVPE) on porous silicon at much lower temperatures than in conventional CVD epitaxy was performed at 823°C and 0.03 mbar using SiCl 2 H 2.

TL;DR: In this paper, the authors have shown that up to 50 wt.% of silver can be added to YBa2Cu3O7−y without degradation of its superconducting transition temperature.

TL;DR: In this article, layers of CdxHg1−xTe have been grown by metal-organic vapour phase epitaxy and doped with arsenic and with phosphorus, which obviates the need for high temperature activation type anneals.

TL;DR: In this article, Sintered specimens of the superconducting ternary oxide, YBa2Cu3Oy, were equilibrated in air or in pure oxygen in the temperature range of 293-932 °C.

TL;DR: In this article, superconducting films of bismuth strontium calcium cuprate were prepared by spray pyrolysis of mixed nitrate solutions onto heated (100) orientated MgO substrates, as well as yttria-stabilized zirconia and SrTiO3.

TL;DR: In this article, a mixed-oxide reaction of Y2O3, BaCO3, and CuO was used to synthesize YBa2Cu3O7−x.

TL;DR: In this article, the chemical interactions between the YBa2Cu3O7−x and various substrates (Si, A12O3, ZrO2, SrTiO 3, MgO, Ag, Cu and Nb) were studied in the temperature range of 600-945°C.

TL;DR: In this article, a double-axis X-ray rocking curve is used to measure the aluminium concentration in GaAlAs grown on GaAs wafers misoriented by 2° from (001).

TL;DR: The reaction mechanisms and dynamics during the formation of the YBa 2 Cu 3 O 7−x compound with tetragonal and orthorhombic structures were studied by DTA and TGA.

TL;DR: In this article, the effect of excimer laser surface melting and resolidification on the near surface chemistry and corrosion properties of AISI 304 stainless steel was investigated, and the results showed that a 30-60% enhancement of Cr at the surface was observed.

TL;DR: In this paper, a double perovskite structure with alternating single copper octahedron sheets and single (Tl, Bi) sheets was proposed, which is closely related to those of the 4-2 phase (La 1− x Sr x ) 4 Cu 2 O 4+δ and the (semiconducting) 2-2-1 phase (Bi 2 (Sr, Ca) 2 Cu 1 O 6+ Δ ).

TL;DR: In this paper, the equilibrium electrical conductivity of YBa 2 Cu 3 O x has been measured as a function of temperature (600 −850°C) and oxygen partial pressure (10 −4 -1 atm).

TL;DR: In this paper, a superconducting Tl2CaBaBa2CuO4 with a Tc of 110 K was prepared by using the single-phase CaBa2cuO4 compound as the Ca and Ba source in the starting powder.

TL;DR: In this article, the microstructure of samples consisting of a 40 nm thick RuO 2 film reactively sputtered on a Si 〈 111 〉 substrate and covered with 20 nm of Al was investigated by high-resolution cross-sectional electron microscopy.

TL;DR: In this paper, two-step heat-treated silicon wafers have been used to determine the electrical activity of bulk stacking faults, and the results show the size and density of the stacking faults are related to the observed electrical activity.