Showing papers in "Materials Research Bulletin in 1991"

TL;DR: The phase relation in the system, (La1−xAx)1−yMnO3+z (A=Sr and Ca), has been investigated by XRD method as discussed by the authors, which showed the A site deficiency in ABO3 perovskite structure, and the range, y, was less than 0.1 when x=0, which decreased with increasing alkaline earth content, x.

TL;DR: In this paper, an explanation for the puzzling high dielectric constant of rutile is sought in a dynamic disordering of the Ti4+ ion, and the Raman spectra were measured on single crystals of stoichiometric and reduced TiO2, at temperatures from 4.2 to 400 K.

TL;DR: Palladium was pyrolytically deposited by a supercritical fluid transport-chemical deposition method using the metal β-diketonate complex bis-(2,2,7trimethyl-3,5-octanedionato)palladium(II) as mentioned in this paper.

TL;DR: A new family of complex copper oxides, HgBa 2 R Cu 2 O 7 (R = La, Nd, Eu, Gd, Dy, Y), has been synthesized and studied by X-ray powder diffraction, transmission electron microscopy and EDS analysis.

TL;DR: In this article, a new X-ray powder diffraction study of RFe6Sn6 (R=Y, GdTm,Lu) compounds points out the occurrence of a long range ordering in these previously reported YCo6Ge6 type structure compounds.

TL;DR: The addition of gold to all of these samples increased their photocatalytic activity as mentioned in this paper, and their catalytic activities were compared to samples of commercial TiO2 (P25).

TL;DR: In this article, single crystals of three AxNbO3 (A = Sr, Ba) reduced niobate cubic perovskites have been obtained by recrystallization of reduced ternary ceramic precursors from borate fluxes under high-vacuum.

TL;DR: In this paper, the evolution of the structure of a poled PbMg 1 3 Nb 2 3 O 3 ceramic is studied by precise X-ray diffraction, between 300 and 5 K.

TL;DR: In this paper, the structure of these phases is orthorhombic with space group Cmcm, as in La3NbO7, and the structure determination has been performed using Rietveld refinement on X-ray powder diffraction data.

TL;DR: A new phase, Ca0.85CuO2, has been synthesized and investigated using powder X-ray and neutron diffraction as mentioned in this paper, which is closely related to that of NaCo2 with chains of edge-shared CuO4 units linking layers of octahedrally coordinated Ca ions.

TL;DR: The crystal structure of deuterated potassium uranyl phosphate trihydrate, KUO2PO4.3D2O, has been simultaneously refined from high resolution powder neutron and synchrotron-radiation diffraction data as mentioned in this paper.

TL;DR: In this paper, the porosity of ferroelectric tungsten bronze Pb0.6Ba0.4Nb2O6 (PBN:60) with and without La3+-modification has been investigated.

TL;DR: The lattice thermal expansion of these three compounds has been determined from x-ray diffraction data at different temperatures ranging from room temperature up to 1000°C as mentioned in this paper, and differences in behaviour are discussed in relation to the structure.

TL;DR: In this paper, a wet-chemical method is described for the deposition of electrically conducting copper sulfide coating on Mn powder phosphors for the electroluminescent (EL) devices working in the direct current (DC) mode.

TL;DR: The perovskite-related layered phase Sr 3 Ru 2 O 7 has been prepared and characterised: electron microscopy and powder X-ray diffraction shows it to be isostructural with Sr 3 Ti 2 O7 as mentioned in this paper.

TL;DR: In this article, the mechanism of magnetite formation from an aqueous alkaline slurry of Fe(OH) 2 was shown to involve the sequence dissolution-oxidation-nucleation on Fe 3 O 4.

TL;DR: In this article, the pyrochlore type for larger cations such as Cs and Tl, and another hexagonal type (a 2-D version of the pyrotechnic type) for divalent cations, such as Ba and Pb, was proposed.

TL;DR: In this paper, a misfit layer structure with unit cell dimensions for the SnSe subsystem was solved by X-ray powder diffraction, and the structure was isostructural with (PbS)1.14NbS2.

TL;DR: In this paper, a monoclinic β-NdAl3(BO3)4 polyhedron with C 2 c and unit cell dimensions, a =7.246(3) A, b =9.343(5) A, c =11.107(3 ) A, β=103.38°, V =731.6 A 3, Z=4, Dc=4.18 g/CM3.596 A.

TL;DR: In this article, strong correlations are observed between delocalized unpaired electrons and adsorbed water molecules in vanadium pentoxide gels V 2 O 5,nH 2 O.

TL;DR: In this paper, the high-temperature superconducting material Bi 2 Sr 2 CaCu 2 O x (2212) was synthesized by reaction of oxides and carbonates.

TL;DR: In this article, three phases, all containing Bi(V), are identified: Sr(Sr.5 Bi.5 )O 2.75 (A); Sr(sr.2 Bi.8 )O 3 (B) and Sr 24 Bi 14 O 52 ( Sr Bi = 1.714 ) (C).

TL;DR: In this paper, the absorption-desorption characteristics of mechanically alloyed mixtures containing 90 wt.% magnesium and 10 wt% NiO, respectively, have been investigated.

TL;DR: In this article, single crystals of Co 2 [C 6 H 2 (COO) 4 ]·18H 2 O were obtained in aqueous silicagel and the crystal structure refinement converged to R g = 0.0350 using 2766 X-ray diffraction intensities.

TL;DR: In this article, the existence of solid solutions of nominal composition Mg 2−x Ca x CuO 3 and Sr 2 −x Ba xCuO 3 has been investigated using powder x-ray diffraction.

TL;DR: In this paper, a room-temperature tetragonal phase is composed of the cationic framework made up of layers perpendicular to the c-axis with a sequence of PbPbSnSn.

TL;DR: In this paper, the phase transition of monophasic oxides of the type YBa 2-x Sr x Cu 3 O 6.7 (0.7) to O 7.0 6.0 is discussed.

TL;DR: In this article, the luminescence properties of Dy3+ and Eu3+ in M3Ln2 (BO3)4 (M = Ca,Sr,Ba; Ln = La, Gd, Y) were systematically studied.

TL;DR: In this paper, preliminary results on the growth of grain-oriented tungsten bronze Ce-doped Sr 1−x Ba x Nb 2 O 6 (SBN) thin films on (100)-oriented Si substrates were reported.