AB2X2-Verbindungen im CaAl2Si2-Typ, VI Zur Struktur von ThCu2P2, YbZn2P2 und YbZnCuP2 sowie der verwandten Verbindungen YbCu3P2 und YbCu2P2
Abstract
X-Ray investigations on the trigonal crystallizing compounds YbZn2P2 (a = 4.035 Å, c = 6.774Å), YbZnCuP2 (a = 3.946 Å, c = 6.462 Å) and ThCu2P2 (a = 4.028 Å, c = 6.469 Å) revealed a CaAl2Si2-type structure.
In order to establish the limits of existence of the CaAl2Si2-type, the new compounds YbCu2P2 and YbCu3P2 have been prepared and structurally solved. YbCu3P2 crystallizes in a trigonal-rhombohedral structure (hexagonal axes: a = 3.964Å, c = 40,296Å, c/a = 10.165, S.G. R[unk]m, Z = 6, all atoms in 6c) with a structure in which Yb-atoms are surrounded by 6 P-atoms in form of a distorted octahedron. They embrace two kinds of blocks, as they are observed in the CaAl2Si2-structure (CuP-blocks) and recognized in Cu3P (Cu2P-blocks). CuP- and Cu2P-blocks show a regular alternating sequenze.
YbCu2P2, for which the structural determination showed the approximate stoichiometry YbCu≈2.2P2, was obtained besides YbP and crystallizes also in a trigonal-rhombohedral structure (hexagonal axes: a = 3.951 Å, c = 59.46 Å, c/a = 15.05, S.G. R[unk]m, Z = 9, Yb(l) in 3a, all other atoms in 6c, three of four Cu-positions partially occupied). The Yb-atoms are also surrounded by P-atoms in a distorted octahedron and include, as in the copper-rich compound, CuP- and Cu2P-blocks. However there are twice as many CuP-blocks as Cu2P-blocks. As the atomic distances show, Ytterbium is probably trivalent in both compounds.
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- Zur Gitterkonstantenbestimmung mit Ausgleichsmethoden
- AB2X2-Verbindungen im CaAl2Si2-Typ, VI Zur Struktur von ThCu2P2, YbZn2P2 und YbZnCuP2 sowie der verwandten Verbindungen YbCu3P2 und YbCu2P2
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- 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
