1,769 research outputs found
The influence of foreign ions on the crystal lattice of barium titanate
From investigations of phase diagrams of ternary oxides the lattice sites of foreign ions and compensating vacancies are established. Large trivalent ions occupy barium sites and are completely compensated by titanium vacancies. Small pentavalent ions occupy titanium sites and are mainly compensated by titanium vacancies. During these investigations a new compound was found, Ba La4 Ti4 O15 isomorphous with Ba5 Nb4 O15
The structure and composition statistics of 6A binary and ternary crystalline materials
The fundamental principles underlying the arrangement of elements into solid
compounds with an enormous variety of crystal structures are still largely
unknown. This study presents a general overview of the structure types
appearing in an important subset of the solid compounds, i.e., binary and
ternary compounds of the 6A column oxides, sulfides and selenides. It contains
an analysis of these compounds, including the prevalence of various structure
types, their symmetry properties, compositions, stoichiometries and unit cell
sizes. It is found that these compound families include preferred
stoichiometries and structure types that may reflect both their specific
chemistry and research bias in the available empirical data. Identification of
non-overlapping gaps and missing stoichiometries in these structure populations
may be used as guidance in the search for new materials.Comment: 19 pages, 13 figure
A mass spectrometric and quantum chemical study of the vaporisation of lead monoxide in a flow of gaseous arsenic and antimony trioxides
Mass spectrometric studies of the vapours over solid lead oxide in a flow of gaseous arsenic and antimony trioxides were conducted. The following ions of the ternary oxides were detected: Pb3As2O6+, Pb3AsO4+, PbAs2O4+, PbAsO2+, PbSb2O4+, and PbSbO2+. The origin of these species produced by the ionisation and/or fragmentation of ternary gaseous oxides is discussed. The PbAs2O4 species was undoubtedly identified by the determination of the appearance energy. Presumably, the Pb3As2O6 and PbSb2O4 species also existed in the gas phase. Thermodynamic data for the ternary oxides were obtained experimentally by means of a mass spectrometric Knudsen-cell method and were confirmed by quantum chemical calculations
The formation and stability of molybdenum-antimony and tungsten-antimony ternary oxides Sb 2MO 6, Sb 2M 2O 9, Sb 2Mo 3O 12 and Sb 4MO 9 in the gas phase (M = Mo, W). Quantum chemical and mass spectrometric studies
The ternary oxides Sb 2MO 6, Sb 2M 2O 9, Sb 4MO 9 (M = Mo, W) and Sb 2Mo 3O 12 were detected in the gas phase by means of mass spectrometry (MS). These gaseous oxides are reported for the first time. Thermodynamic data was obtained experimentally and confirmed by quantum chemical (QC) calculations. In addition, structural data on these molecules was obtained. The ionisation potentials (IP) were also determined both experimentally and theoretically. © 2012 The Royal Society of Chemistry
Crystal Structure and Thermal Behavior of SbC2O4OH and SbC2O4OD
The order of OH groups in the crystal structure of SbC2O4OH, a potential precursor in the synthesis of ternary oxides, was debated. Neutron diffraction on the deuteride SbC2O4OD revealed disordered OD groups with half occupation for deuterium atoms on either side of a mirror plane (SbC2O4OD at T = 298(1) K: Pnma, a = 582.07(3) pm, b = 1128.73(5) pm, c = 631.26(4) pm). O–H stretching frequencies are shifted by a factor of 1.35 from 3390 cm−1 in the hydride to 2513 cm−1 in the deuteride as seen in infrared spectra. SbC2O4OH suffers radiation damage in a synchrotron beam, which leaves a dark amorphous residue. Thermal decomposition at 564 K yields antimony oxide, carbon dioxide, carbon oxide, and water in an endothermic reaction. When using SbC2O4OH as a precursor in reactions, however, ternary oxides are only formed at much higher temperatures
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