Die Kristallstruktur der ferroischen Verbindung Pb3[O|GeO4]
Abstract
Light yellow single crystals of Pb3[O|GeO4], a ferroelastic and possibly antiferroelectric compound, were grown from melt by spontaneous crystallization. The crystal data are a = 5.260(1), b = 10.437(2), c = 5.477(1) Å, and β = 92.55(3)°; space group P2l; Dobs = 8.52(5), Dx = 8.560 g · cm−3 for Z = 2. X-ray powder data are given. The crystal structure has been determined by means of 1464 unique reflections, collected with an automated 4-circle diffractometer using Mo Kα radiation. The final R value was 0.075. The comparatively simple crystal structure consists of isolated [GeO4]4− tetrahedra connected by three non-equivalent Pb atoms with similarly pyramidal arrangement of four nearest oxygen neighbours at distances below 2.71 Å. The dipol moments of the Pb polyhedra point to channels extending parallel to [001]. In addition one oxygen atom O(5) occupies an octahedral hole between the Pb atoms laying out of center covalently bonded to three of them by short bonds of 2.159, 2.268 and 2.323 Å in length. The Ge —O tetrahedral distances range from 1.728 to 1.789 Å. Prominent ferroelastic (100) domain walls in the twinned crystals correspond structurally to an axial b glide plane.
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Articles in the same Issue
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- Zur Gitterkonstantenbestimmung mit Ausgleichsmethoden
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- Die Kristallstruktur der ferroischen Verbindung Pb3[O|GeO4]
- Absorption corrections for equatorial back-reflections from a thin highly-absorbing plate-shaped crystal
- Posnjakite: 2∞[Cu4(OH)6(H2O)O] octahedral sheets in its structure
- Use of the integrated minimum function in heavy-atom structures
- Crystal growth, structure, and physical properties of Bi2Ge3O9
- Electrogyration effect in the paraelectric phase of ferroelectric alums
- Feldspar-paracelsian dimorphism of the synthetic compounds (Sr,Ba)[(Al,Ga)2(Si,Ge)2O8]
- Non-existent silicates
- Crystal synthesis and structure refinement of high-pressure ScAlO3 perovskite
- A new phase of coesite SiO2
- Verfeinerung der Kristallstruktur des Silberperchlorats AgClO4
- The Neutron scattering amplitude of Uranium
- Kleber, W.: Einführung in die Kristallographie. 13., stark überarbeitete Auflage. 392S., 358 Abb., 45 Tafeln und 1 Beilage. Berlin: VEB Verlag Technik 1977. Geb. DM 32,– ; DDR M 24,80
- Lockwood, E. H., Macmillan, R. H.: Geometrie Symmetry (Geometrische Symmetrie). 288 S., mit zahlreichen Abbildungen und Tabellen. Cambridge: Cambridge University Press 1978. £10.50
Articles in the same Issue
- Die Kristallstruktur von PbGe3O7 mit Ge4 + in trigonal-dipyramidaler neben tetraedrischer Koordination
- Zur Gitterkonstantenbestimmung mit Ausgleichsmethoden
- AB2X2-Verbindungen im CaAl2Si2-Typ, VI Zur Struktur von ThCu2P2, YbZn2P2 und YbZnCuP2 sowie der verwandten Verbindungen YbCu3P2 und YbCu2P2
- Die Kristallstruktur der ferroischen Verbindung Pb3[O|GeO4]
- Absorption corrections for equatorial back-reflections from a thin highly-absorbing plate-shaped crystal
- Posnjakite: 2∞[Cu4(OH)6(H2O)O] octahedral sheets in its structure
- Use of the integrated minimum function in heavy-atom structures
- Crystal growth, structure, and physical properties of Bi2Ge3O9
- Electrogyration effect in the paraelectric phase of ferroelectric alums
- Feldspar-paracelsian dimorphism of the synthetic compounds (Sr,Ba)[(Al,Ga)2(Si,Ge)2O8]
- Non-existent silicates
- Crystal synthesis and structure refinement of high-pressure ScAlO3 perovskite
- A new phase of coesite SiO2
- Verfeinerung der Kristallstruktur des Silberperchlorats AgClO4
- The Neutron scattering amplitude of Uranium
- Kleber, W.: Einführung in die Kristallographie. 13., stark überarbeitete Auflage. 392S., 358 Abb., 45 Tafeln und 1 Beilage. Berlin: VEB Verlag Technik 1977. Geb. DM 32,– ; DDR M 24,80
- Lockwood, E. H., Macmillan, R. H.: Geometrie Symmetry (Geometrische Symmetrie). 288 S., mit zahlreichen Abbildungen und Tabellen. Cambridge: Cambridge University Press 1978. £10.50
