Showing papers in "Materials Research Bulletin in 1969"

TL;DR: In this paper, the preparation and properties of three oxygen deficient pyrochlores are reported and the stability of this defect-pyrochlore structure relative to the perovskite structure is discussed.

TL;DR: The crystal structure of lithium titanate has been determined using x-ray diffraction patterns from flux-grown single crystals supplied by George Uhlig as mentioned in this paper, and the mean bond lengths, Li-O 2.14A and Ti-O 1.95A, compare favorably with other oxides.

TL;DR: Transparent Y2O3 specimens have been fabricated by vacuum hot pressing in graphite dies at temperatures ranging from 1300-1500°C for 1-2 hours as discussed by the authors. But their optical transmittance was greater than 80 percent to six microns in the infra-red.

TL;DR: A survey of the known compounds in the system Y 2 O 3 SiO 2 and their several crystalline phases is given in this article, where the preparation of Y 2 SiO 5, of three modifications of y 2 Si 2 O 7 and of the -probably impurity-stabilized-apatite and garnet structures of yttrium silicate is described.

TL;DR: The structure of the SiC phase in the system silicon carbide-boron carbide and carbon has been studied in the range 2200-2550°C as discussed by the authors and the solubility of boron in α-SiC at 2450-2500°C has been shown to be less than 0.2 wt.

TL;DR: In this paper, the phase relation and electric and magnetic properties of Li x V 2−x O 2 were studied in the temperature range from liquid helium to 400°C, and the one phase region was determined to be in the range of 0.8≤x≤1.2 in Li xV 2−X O 2.

TL;DR: In this article, the infrared properties of amorphous Se are discussed in terms of a superposition of spectra due to Se8 ring molecules and polymeric chains Seμ.

TL;DR: In this paper, complete liquidus and solidus equilibria have been established by DTA and quench techniques in the system NaNbO 3 BaNb 2 O 6, which contains the pseudo-tetragonal bronze NaBa 2 Nb 5 O 15, while little solid solution occurs in the end member compounds.

TL;DR: The importance of the anion coordination change is illustrated for transformations of In203 and the transition metal molybdates in high pressure phase transformations as mentioned in this paper, and the relative change of molar volume or density can frequently be used to distinguish high-pressure phase transformations involving a coordination change from those not involving coordination change.

TL;DR: In this paper, a Ba, Sr, Na niobate series with tetragonal tungsten bronze-like structures is presented, where spontaneous polarization (P S ), dielectric constant (e), and voltage for half-wave retardation (V π ) of 0.38 ± 0.6328μ radiation, all at room temperature, are given for single crystals.

TL;DR: A series of rare earth compounds LnCrTeO6 has been prepared and X-ray investigation shows their structure is related to the PbSb2O6 structure.

TL;DR: In this article, the stability region of a quenchable high pressure modification, Li3BN2(W), was defined, and the data also suggest the possibility of another nonquenchable, non-convex, high-pressure modification.

TL;DR: In this article, the dark conductivity of CdS as a function of the sulfur vapor pressure is investigated during heat treatment in a temperature range 500° j ∼ p S −1 m with m = lx, l being the average number of sulfur atoms per sulfur molecule in the gas phase.

TL;DR: The phase equilibrium diagram for the ternary system Na 2 O-BaO-Nb 2 O 5 has been determined around the compound barium sodium niobate (nominally Ba 2 NaNb 5 O 15 ).

TL;DR: In this paper, a simple low-temperature D.T.A. set-up, designed for measurements in the temperature region 120°K -600°K, is described.

TL;DR: In this article, it was confirmed that AgSbO3 has pyrochlore-related structure without being hydrated, and attempts to prepare Ag2Sb2O5(OH)2 or Ag2 Sb2 O5F2 were unsuccessful.

TL;DR: In this article, rare earth compounds containing C1 that are activated by Er, Ho and/or Tm and sensitized by Yb can emit visible radiation with considerable efficiency when excited by 0.93μ radiation from a GaAs: Si diode.

TL;DR: In this paper, the relations between structures and magnetic properties of some compounds with formula M Fe F 3 are discussed and the exchange interaction integrals are calculated by the Bethe-Peierls-Weiss methods.

TL;DR: In this article, a study of ferrimagnetic resonance line-width properties of a series of polycrystalline O12 samples with 0 ≤ x ≤ 0.8 and 0.3 ≤ y ≤ ε ≥ 0.7 is presented.

TL;DR: The position of the eutectic point in the system Al 2 O 3  Y 3 Al 5 O 12 has been reestablished at 80.1 ± 0.1 mol% Al 2O 3 − 18.7 ± 0.1 mol % Y 2 O3 ) at 1800° ± 5°C, Microstructures of various compositions in this system which had been melted in a vacuum graphite resistance furnace were observed.

TL;DR: In this paper, electron optical observations of several different mixed oxides of niobium having structures related to those of cubic rhenium trioxide and tetragonal tungsten bronze are presented.

TL;DR: In this article, the authors describe chemical preparations and give crystal data for three new compounds: BaMg2(AsO4)2, BaCo2(AO4), and BaNi2(PO4), which is an isomorph of BaNi 2(O4).

TL;DR: In this article, the authors examined the effect of interfacial flow on the film thickness and found that it is relatively constant for laminar free convection and for a rotating disk in a gas.

TL;DR: In this article, the X-ray intensity curves of solid amorphous As and Se were discussed and the dimensions of the structure element of the respective lattice were obtained from the analysis of the intensity curves.

TL;DR: The titanates of rare earths from Gd through Lu, and of Y, have been prepared by heating RE 2 O 3 and TiO 2 in an evacuated silica capsule at 1200°C as discussed by the authors.

TL;DR: In this paper, the silicates, zircon and hafnon were synthesized from the constituent oxides, and the synthesis was essentially complete after heating for 24 hours at 1450°C.

TL;DR: In this paper, the existence of the glassy modification of the semiconducting compound CdGe x As 2 for x = 0.02 to 1.3 was proved and the correlation between physicochemical properties of the melts and their ability to form a glass by cooling was shown.

TL;DR: Ferroelectric domain walls have been studied by means of electron microscopy in Bi 4 Ti 3 O 12 as mentioned in this paper, and two essentially different types of walls for which the polarization vectors enclose roughly 180° or 90°, can be distinguished on diffraction evidence.

TL;DR: In this paper, the authors showed that at room temperature, the La atoms occupied sites I, I′, II and V at 425 and 735°C in a helium stream, respectively.

TL;DR: The divalent vanadium compounds, NaVF3, KVF4, and RbVF5, have been prepared and magnetic susceptibility measurements showed large negative paramagnetic Curie temperatures, but no evidence of long-range antiferromagnetic order.