Zur Kristallstruktur von ( Cu , Mn ) UMo3O12/On the Crystal Structure of (Cu, Mn )UMo3O12

1996 ◽  
Vol 51 (3) ◽  
pp. 450-452 ◽  

Abstract Single crystals of (Cu,Mn)UMo3O12 have been prepared in sealed copper tubes. X-ray investigations lead to hexagonal symmetry, space group C6h2-P63/m a = 9.7895 (13), c = 6.202(1) Å , z = 2. (Cu,Mn)UMo3O12 is isotypic to CdThMo3O12. Calculations of the Coulomb terms of lattice energy with respect to different oxidation states of copper, molybdenum and uranium and the previously described pair of isotypic compounds of CdThMo3O12 to Na2ThRe6O24 are discussed.

1998 ◽  
Vol 53 (3) ◽  
pp. 287-290 ◽  
Author(s):  
B. Wedel ◽  
L. Wulff ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of Pb2TeO5 have been prepared by flux techniques. X-ray investigations showed a new crystal structure with monoclinic symmetry, space group C4S -Cc, a = 13.099(3), b = 5.714(1), c = 7.520(2) Å, β = 123,80(3)°, Z = 4. Pb2TeO5 is characterized by 1∞[TeO5] chains of octahedra isolated from each other and incorporated into an edge, corner and face connected frame of PbO7 polyhedra. Possible positions of the lone pair of electrons of Pb2+ are estimated by calculations of Coulomb terms of lattice energy.


1995 ◽  
Vol 50 (2) ◽  
pp. 252-256 ◽  
Author(s):  
H. Szillat ◽  
Hk. Müller-Buschbaum

Single crystals of AgKCu3Mo4O16 have been prepared by crystallization from melts and investigated by X-ray diffractometer techniques. This compound crystallizes with monoclinic symmetry, space group C2h5 - P21/c, a = 5.056(1), b = 14.546(4), c = 19.858(9) Å, β = 86.64(5)°, Z = 4. The crystal structure of AgKCu3Mo4O16 is closely related to K2Cu3Mo4O16 showing ribbons of edge-sharing CuO6 and AgO7 polyhedra. The ribbons are linked by tetrahedrally coordinated molybdenum and K2O10 groups. Another kind of MoO4 tetrahedra occupies the cavities inside the ribbons. The crystal structure and the coordination of silver, copper, potassium and molybdenum by oxygen are discussed with respect to K2Cu3Mo4O16.


1995 ◽  
Vol 50 (4) ◽  
pp. 585-588 ◽  
Author(s):  
S. Frenzen ◽  
Hk. Müller-Buschbaum

Single crystals of Ba9Ru3.2Mn5.8O27 have been prepared by flux techniques. X-ray four circle diffractometer measurements led to trigonal (rhombohedral) symmetry, space group D53d - R3̄̄̄m , a = 5.7043(5), c = 21.255(4) Å , Z = 1. This phase is isotypic to BaRuO3. The crystal structure and the occupation of the M3O12 triple octahedra by ruthenium and manganese are discussed with respect to other oxides containing M3O12 groups in an ordered and disordered way.


1998 ◽  
Vol 53 (5-6) ◽  
pp. 527-531 ◽  
Author(s):  
B. Wedel ◽  
K. Sugiyama ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of Pb3Ni4.5Te2.5O15 have been prepared by heating pellets of mixtures of PbO, TeO2 and nickel hydroxide carbonate to 730 °C in air. X-ray investigations led to hexagonal symmetry, space group d66-P6322, lattice constants a = 10.2589(1), c = 13.554(5), Z = 4. Typical features of the crystal structure are face sharing TeNiO9 octahedra doubles and planes of connected (TeO6)6 and (TeO6)3(NiO6)3 hexagons. The one-sided coordination of lead by oxygen is complemented by the lone pair of electrons. The lone pair positions are estimated by calculations of the Coulomb terms of lattice energy.


1998 ◽  
Vol 53 (3) ◽  
pp. 283-286 ◽  
Author(s):  
L. Wulff ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of the hitherto unknown compound SrMnTeO6 have been prepared from Sr(OH)2 ·8H2O , MnCO3(aq) and TeO2 in air by crystallization below the melt range. X-ray investigations showed hexagonal symmetry, space group D33h -P6̅2m, lattice constants a = 5.143( 1), c = 5.384(2) A, Z = 1. SrMnTeO6 is characterized by staggered [(Mn/Te)6O18] Kagome layers along [001]. These layers are connected by Sr2+ ions, resulting in SrO6 prisms isolated from each other. The structure is discussed with respect to the connection of Kagome nets in the quaternary oxides of the Ba3Ln4O9 type.


1994 ◽  
Vol 49 (3) ◽  
pp. 355-359 ◽  
Author(s):  
F.-D. Martin ◽  
H. Müller-Buschbaum

Abstract Single crystals of KBaCuV2O7Cl have been prepared by a flux technique and investigated by X-ray analysis. The compound crystallizes with tetragonal symmetry, space group C24v-P4 bm, a = 8.8581, c = 5.4711 Å, Z = 2. The crystal structure shows Cu2+ within a one sided strongly distorted CuO4Cl2 octahedron. The copper ion is shifted towards the nearer Cl- neighbour to form a CuO4Cl square pyramid. Two VO4 tetrahedra are connected to give stretched V2O7 double tetrahedra, and linked in planes via the oxygen corners of the CuO4Cl pyramids. The crystal structure and the structure of the complex BaO8Cl2 polyhedron are discussed.


1995 ◽  
Vol 50 (6) ◽  
pp. 879-883 ◽  
Author(s):  
H. Szillat ◽  
Hk. Müller-Buschbaum

Single crystals of Ag0.5Cu3V0,5Mo2,5O12 have been prepared by crystallization from melts and investigated by X -ray methods. They crystallize with triclinic symmetry, space group Ci1 -P 1̄ , a = 6.797(6), b = 8.575(6), c = 9.897(7) Å, α = 103.47(6), β = 103.69(6), γ = 101.48(6)° and Z = 4. The crystal structure is characterized by chains of edge-sharing CuO6 octahedra and CuO5 pyramids. Special features of this com pound are the square planar surrounding of Ag+ by O2− and a statistical distribution of molybdenum and vanadium at one point position.


1998 ◽  
Vol 53 (5-6) ◽  
pp. 628-630 ◽  
Author(s):  
O. Sfreddo ◽  
Hk. Muller-Buschbaum

Abstract The compounds Ba4Nd4Zn3PtO15; (I) and Ba4Eu4Zn3PtO15 (II) crystallize with hexagonal symmetry, space group C46V-P63mc, (I): a = 11.719(1), c = 6.778(1) Å, (II): a = 11.654(1), c = 6.778(1) Å, Z = 2. Both belong to the Ba6Nd2-. AI4O15 type when replacing 2Ba2+ by 2Ln3+ and 4Al3+ by 3Zn2+ + Pt4+. The tetrahedrally coordinated Al3+ is substituted by Zn2+, the octahedrally one by Pt4+. Due to the similarity of X-ray scattering of Ba2+ and Ln3+ the ordered replacement of Ba2+ by Ln3+ has been proven by calculations of the Coulomb terms of lattice energy.


1996 ◽  
Vol 51 (3) ◽  
pp. 447-449 ◽  
Author(s):  
O. Sedello ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of (Cu,Mn)3.66Mo3O12 have been prepared in sealed copper tubes. X-ray investiga­tions lead to orthorhombic symmetry, space group D2h16-Pnma, a = 5.1541(9), b = 10.788(2), c = 18.114(3)) Å , Z = 4. (Cu,Mn)3.66Mo3O12 is iso­typic to NaCo2.31Mo3O12 and (Cu,Co)3.75Mo3O12 with split positions for two of the metals.


1997 ◽  
Vol 52 (5) ◽  
pp. 553-556 ◽  
Author(s):  
O. Sfreddo ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of Ba13Dy8Zn4Pt4O37 have been prepared by reaction of mixtures of BaCO3, ZnO and DyO3 at temperatures up to 1225 °C using platinum crucibles. X-ray investigations led to a new crystal structure with tetragonal symmetry, space group C4h5-I4/m, a = 18.659(7), c = 5.734(2) Å, Z = 2. The structure is characterized by PtO6 and BaO6 octahedra as well as by tetragonal ZnO5 pyramids and single capped trigonal prisms of oxygen around dysprosium. The remaining barium positions show coordination numbers of nine and ten. The crystal structure has large ∞1[(PtDy4O)6)4] polyhedra tunnels. Considering the ∞1[Ln4O16]20- polyhedra groups some parts of the structure show similarities to BaZnLn2O5, Ba5Zn4Ln8O21 and Ba2Ln2ZnPtO8.


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