Showing papers in "Journal of Solid State Chemistry in 1990"

TL;DR: Seebeck coefficient and electrical conductivity measurements were performed for undoped and Sr-doped LaMnO 3 as a function of temperature and oxygen partial pressure, and the results showed typical p-type behavior as mentioned in this paper.

TL;DR: Transparent and stable manganese dioxide gels are obtained upon reduction of permanganate aqueous solutions AMnO4 [A = Li, Na, K, NH4, N(CH3)4] by fumaric acid as discussed by the authors.

TL;DR: In this article, the authors highlight the important roles played by crystal chemistry in controlling the superconductive properties of the intergrowth structures of the copper oxides and show that the coordination geometry preferred by different oxidation states of Cu appears to control the oxygen ordering and the Tc variation in the YBa2Cu3O6+x system.

TL;DR: In this article, the systematics in the transition metal d-d Coulomb interactions and the anion to cation charge transfer energies were discussed, and the nature of the optical thresholds and their dependence on the cation and anion electronegativity were discussed.

TL;DR: Sintered specimens of cubic Sc2O3-type structure (C-type, Ia 3 ), Sc 2O3, Y2O-3, Sm 2 O3, and In 2 O 3, and powdered specimens of C-type Gd2O 3 were studied by X-ray powder diffraction analysis at room and high temperature as mentioned in this paper.

TL;DR: In this article, the average-valence phase of the rhombohedrally distorted perovskite Sr{sub 2}LaFe{sub 3}O{sub 8.94} has been refined from neutron powder diffraction data collected at room temperature (spacegroup R{bar 3}c, a = 5.4580 {angstrom}, {alpha} = 60.19{degree}.

TL;DR: In this paper, the phase relationships in the CuO-rich region of these ternary diagrams progressively change from the La system through the Nd, Sm, Eu, Gd, Y, Ho systems to the Er system.

TL;DR: In this article, carbonate ions which replace phosphates and hydroxide ions in bone and synthetic apatites were studied by 13C and 1H solid state NMR spectroscopy.

TL;DR: In this paper, the potential around the M atom with trigonal bipyramidal coordination has double minima in all the magnetoplumbite-type crystals at lower temperatures.

TL;DR: Sr2N has been synthesized from the elements and its structure determined by time-of-flight neutron diffraction as mentioned in this paper, which is a metallic conductor with a weak temperature-independent paramagnetism.

TL;DR: In this article, the conductivities and Seebeck coefficients of the BaFeO3−δ perovskites were measured in air, O2, and N2 in the temperature range from 650°C to room temperature.

TL;DR: In this paper, the compounds SrVO3 and Sr2VO4 have been synthesized by decomposition of the nitrates in air followed by high purity hydrogen reduction and they have been studied by X-ray and neutron diffraction measurements.

TL;DR: In this paper, the synthesis and physical properties of the ternary nitride CaNiN were reported, which was prepared by the reaction of Ca{sub 3}N{sub 2} and Ni in 1,000{degree}C. The structure, determined by the method of x-ray powder diffraction, is tetragonal (P4{ sub 2}/mmc) with a = 3.5809(2) {angstrom}, c = 7.0096(3) {ngstrom}, and Z = 2.

TL;DR: The absolute values of oxygen nonstoichiometry were determined by the direct reduction in a flux of hydrogen (TGA) or by decreasing P{sub O{sub 2} in a coulometric titration cell as mentioned in this paper.

TL;DR: In this paper, a perovskite of the K2NiF4 structure was synthesized and the formal valence of vanadium is 4+ and the octahedra surrounding the vanadium are elongated.

TL;DR: In this article, the powder X-ray structure analysis of VO2(A) has been performed by the use of EXAFS and the Rietveld method; possible structure models based on the ex-AFS results were examined by the Rieveld analysis.

TL;DR: The septenary compound (Tl 0.5Pb0.5) (Ca1−yYy)Sr2Cu2O7−δ system as Ca2+ is replaced by Y3+. Superconductivity is observed over the homogeneity range y = 0.6-1.0, the material undergoes a metal-semiconductor transition as discussed by the authors.

TL;DR: In this article, the authors refined the CuO structure from time-of-flight neutron diffraction data collected at 11 K and showed that the distance of the Cu-O distances are 1.951(1) and 1.961 (1) A (each 2 ×) with corresponding OCu-O angles of 84.315(7)° and 95.68°, respectively.

TL;DR: In this article, the 6H perovskites Ba3NiRu2O9 and Ba3CoRu 2O9 have been refined from neutron powder diffraction data collected at 5 or 2 K.

TL;DR: In this article, the authors present results of a computer modeling study of the technologically important material SnO2, focusing on the properties of defects and dopants and show that vacancy energies are high, leading to limited deviations from stoichiometry.

TL;DR: A vanadium oxyhydroxide H{sub 2}V{sub 3}O{sub 8} with a green fibrous shape was hydrothermally synthesized as mentioned in this paper.

TL;DR: In this article, the luminescence and the quantum efficiency of the phosphors CaSO{sub 4}:Eu{sup 3+} and CaSO-sub 4:Ce{sup3+} are reported and attributed to a decrease of the concentration of vacancies in the lattice.

TL;DR: In this paper, the authors investigated the crystal chemistry and phase stability of the mixed rare earth systems La 2− x RE x CuO 4 (RE = NdY) and found a definitive correlation between the size of the RE cation and structure, and the stability limits of the related K 2 NiF 4 (T )-, Nd 2 CuO4 (T′ )-, and hybrid T∗ -type structures.

TL;DR: An ab initio structure determination of synthetic volborthite Cu 3 V 2 O 7 (OH) 2, 2H 2 O was performed from X-ray and neutron powder data using a modified Rietveld method as discussed by the authors.

TL;DR: In this article, solid-solutions of the type Nd 2− x Sr x NiO 4+ δ (0 ≤ x ≤ 1) were prepared by codecomposition of the metal nitrates and were characterized by means of powder X-ray diffraction, TGA, electrical resistivity, and magnetic susceptibility measurements.

TL;DR: In this paper, the authors describe the reversibility of the recrystallization of the aluminophosphate molecular sieve VPI-5 to ALPO{sub 4{sup {minus}8}.

TL;DR: In this paper, a novel combustion process using corresponding rare earth nitrate, aluminum nitrate and urea/carbohydrazide mixtures was described, and a saturated aqueous solution of the mixture when rapidly heated at 500°C foams and ignites to yield voluminous, crystalline single phase rare earth orthoaluminates.

TL;DR: In this paper, the phase relations in the In2O3Fe2ZnO4 ZnO system at 1350°C were determined by means of a classical quenching method.

TL;DR: In this article, a model for the five-and seven-layer lamellae is presented, based on a modified cut and projection method, derived from the (approximate) q -values of the (quasi)commensurate diffraction patterns.