Showing papers in "Materials Research Bulletin in 1979"

TL;DR: In this article, the chemical stability of perovskites LaBO3 where B = V, Cr, Mn, Fe, Co, Ni was studied by thermogravimetry at 1000°C in gas mixtures of CO 2 H 2, O 2 CO 2 and O 2 Ar at 1 bar.

TL;DR: The structure of BiVO 4 was refined at 4.5, 295 and 566k from powder neutron diffraction data and at 295K from powder X-ray diffraction by the Rietveld profile technique as mentioned in this paper.

TL;DR: The argyrodites as mentioned in this paper are a family of tetrahedrally close-packed structures with a common cubic HT-structure with a disordered A-cation sublattice.

TL;DR: In this paper, various compositions (x from 1 to 3) were obtained from chemically coprecipitated powders, and the 1.6-approximation was obtained from a single sample.

TL;DR: In this article, high conductive and transparent thin films of SnO 2 : F and In 2 O 3 : Sn have been prepared using the simple pyrolitic (spray) method.

TL;DR: In this article, a new crystallochemical principle was proposed which allows a coherent description of the A-low temperature form, the H and the X forms, resulting from a partial oxygen disorder can be assumed either by a static or dynamic model.

TL;DR: In this article, a synthetic process for the preparation of both pure and doped lead zirconate titanate solid solution powders is presented, based on the reaction of the constituent oxides, or their precursors, in a molten salt solvent.

TL;DR: In this article, three solid phases in the ambient temperature system Li/sub x/V/sub 2/O/sub 5/ (0.1 < x < 1.0) have been synthesised and characterised.

TL;DR: In this article, the crystal field plays an important role in the self quenching process of neodymium 4F3/2 level and a limit to the easily available ground state splitting is given.

TL;DR: A second order phase transition has been found in Na3Zr2Si2PO12 by three independent techniques as mentioned in this paper, including ac-impedance and X-ray diffraction powder patterns, and specific heat measurements showed a clear indication of a phase transition at 420 K with ΔH = 2.07 kJ mol−1.

TL;DR: In this article, a stoichiometric strontium cobaltite oxide was prepared at 910°C in air and characterized by chemical analysis and X-ray diffraction.

TL;DR: In this article, a monoclinic space group P 2 1 a with a = 15.707, b = 9.231, c = 18.204 A and β = 125.25° was solved by the direct method and Fourier technique, and refined by least squares to an R = 0.028.

TL;DR: In this paper, the electrical resistivity of graphite has been studied as a function of stage and temperature from 100 K to 300 K. The results are discussed with respect to the graphite -heavy alkali metal compounds.

TL;DR: In this paper, the effect of dehydration on site occupancy and molecular sorption in mordenite is discussed. But the authors do not consider the effect on the domain structure.

TL;DR: In this article, the pyrolitic spray method was used to obtain high conductive and transparent thin films of SnO 2 :F and In 2 O 3 :Sn. The conditions of preparation were described.

TL;DR: In this article, a PZT/polymer composites electromechanically and physically comparable to the Skinner replamine composites were discussed, which were simplified by the use of a compacted mixture of volatilizable plastic spheres and pZT powder, which when sintered yields a piezoelectric with a density of less than 2.9 g/cm 3, a permittivity of ∼120 and a d 33 of 180×10 −12 C/N.

TL;DR: In this article, the variation of the ionic conductivity is discussed as a function of Li2O and LiX concentration and the choice of the halogen is taken in consideration.

TL;DR: In this article, the ion exchange properties of the ATiMO 5 oxides (M = Ta, Nb), with a layer structure, were shown for the first time, by action of an acid solution on the oxides, the HTiMO5 oxides were synthesized.

TL;DR: In this article, the authors extend Landauer's effective medium model to see if the observations are consistent with a high conductivity layer forming on each non-conducting particle, provided one assumes the layer a few hundred Angstroms thick.

TL;DR: Amorphous MoS3, prepared by chemical or thermal decomposition of ammonium thiomolybdate, has been found to react readily with n butyl lithium and sodium and potassium naphthalides to give compositions MxMoS3 (0 ≤ x ≤ 4, M = Li, Na, K) as mentioned in this paper.

TL;DR: In this article, the authors analyzed the chemical states and the concentrations of Mg and Ni at the surface of the hydrogen storage materials MgMg2Ni eutectic alloy and Mg 2Ni intermetallic compound.

TL;DR: In this article, a polycrystalline sample of the spinel NiCo 2 O 4 prepared at 320°C revealed 92% occupancy of the tetrahedral (A) sites by cobalt and Neel ferrimagnetism with mean A-site and B-site moments 〈 μ A 〉 = 2.29(9) μ B and 〆 μ B 、 = −0.97(13) μ C.

TL;DR: In this paper, the ionic conductivity of sheet phases A x (L x M 1−x )O 2 with trigonal prismatic or octahedral environment of the alkali ions has been compared.

TL;DR: In this article, the LnMg/sub 12/, Ln/sub 2/Mg-sub 17/ and Lnmg/ sub 5/MG/sub 41/ alloys (Ln = La, Ce or mischmetal) were investigated.

TL;DR: In this article, the thermal intercalation of pyridine with 2H-TaS2 is associated with redox reactions involving guest layers and host molecules, and the reaction product is discussed in terms of a novel ionic bonding concept.

TL;DR: An oxygen-deficient perovskite of composition SrFeO3−x selectively absorbs NO gas above approximately 100°C, and the analysis of the infrared spectrum of the system 14NO - 15NO - SIRF 3−x has revealed that the absorbed species in the system is possibly the nitrosyl ion (NO−) bound to the iron ion accomodating some oxygen vacancies as mentioned in this paper.

TL;DR: In this article, a defect anti-fluorite structure with 10% of the lithium sites being vacant has been investigated in the temperature range from 25 to 400/sup 0/C and the electronic contribution to the total conductivity is smaller by a factor of less than 10/sup -4.

TL;DR: In this paper, the dependence of the crystal structure of FeTiDx on D2-pressure (≤153 bar) was investigated at room temperature by means of neutron diffraction on powder samples both in absorption and desorption.

TL;DR: In this article, the electrostriction in Pb (Zn 1 3 Nb 2 3 ) O 3 crystals has been investigated using a strain gauge method in the ferroelectric phase below 140 C.

TL;DR: A high-temperature form of a brownmillerite-like compound Sr2Fe2O5, which has a perovskite structure with the oxygen vacancies randomly distributed, showed a remarkable NO decomposition at 700-900°C as mentioned in this paper.