Darstellung und Strukturbeschreibung von NaCa3 Mn(V2O7)(V3O10) / Preparation and Structure of NaCa3Mn(V2O7)(V3O10)

1998 ◽  
Vol 53 (5-6) ◽  
pp. 507-511 ◽  
Author(s):  
R. Rettich ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of NaCa3 Mn(V2O7)(V3O10) have been prepared by crystallization from flux in argon atmosphere. X-Ray single crystal methods led to triclinic symmetry, space group C1i - P 1̄, a = 6.8798(9), b = 6.902(1), c = 15.480(2) Å, α = 87.39(1), β = 85.32(1), γ = 86.25(2) °, Z = 2. The compound belongs to the rare trivanadates showing V2O7 and V3O10 groups incorporated into a NaCaMn/O framework. One point position of the cations is occupied by Ca2+, three by Na+ and Ca2+ in a statistical distribution and a fourth one by Mn2+. The surrounding of Mn2+ and the statistically occupied position M(3) are octahedra, the other metal positions are centers of capped trigonal prisms.

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.


1994 ◽  
Vol 49 (8) ◽  
pp. 1141-1144 ◽  
Author(s):  
F.-D. Martin ◽  
Hk. Müller-Buschbaum

Single crystals of KBa2V2O7Cl were prepared by crystallization from flux. The transparent crystals crystallize with hexagonal symmetry, space group D46h-P63/mmc, a = 5.7688, c = 15.0762 Å. Z = 2. KBa2V2O7Cl is characterized by V2O7 double tetrahedra and a statistical distribution of K+ and Ba2+ surrounded by nine O2- and one Cl-. One point position occu­pied by Ba2+ shows a 3 + 6 + 3 anti-cuboctahedral coordination. KBa2V2O7Cl is isotypic to K3Mo2O7Br.


1995 ◽  
Vol 50 (5) ◽  
pp. 707-711 ◽  
Author(s):  
H. Szillat ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of (Cu,Co)3,75Mo3O12 have been prepared by recrystallization from melts and investigated by X-ray diffractometer techniques. The compound crystallizes with orthorhombic symmetry, space group D162h-Pnma, a = 5.092(1), b = 10.624(3), c = 17.804(4) Å, Z = 4 and is isotypic to NaCo2.31Mo3O12. The crystal structure is discussed and it is shown, that the trigonal prismatically coordinated copper positions are occupied in a different manner. One of the alternate sites is beside the centre of the prisms, and the other one is shifted towards one of the faces of the rectangular prism. This detail may be interpreted by assigning the valance states CuI and CuII. The MO6 octahedra are occupied statistically by copper and cobalt.


1996 ◽  
Vol 51 (7) ◽  
pp. 912-916 ◽  
Author(s):  
Anne Utzolino ◽  
Karsten Bluhm

The compounds MnCo(B2O5) (I) and MnMg(B2O5) (II) were prepared by using B2O3 flux techniques in an argon atmosphere. X-ray investigations on single crystals showed triclinic symmetry, space group Ci1 - P1̄, I: a = 320.94(10), b = 619.20(11), c = 939.0(2) pm, a = 104.38(2)°, β = 90.76(2)°, γ = 92.046(14)° and II: a = 318.97(7), b = 619.8(2), c = 936.7(2) pm, α = 104.47(2)°, β = 90.60(2)°, γ = 91.98(2)° Z = 2. Their structures are isotypic with Co2(B2O5). All metal ions are octahedrally coordinated by six oxygen atoms. The structures contain diborate anions B2O54-. Each boron atom is threefold coordinated by oxygen.


1996 ◽  
Vol 51 (4) ◽  
pp. 485-488 ◽  
Author(s):  
S. Frenzen ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of Ag0.4Na2.3Ca4.3RuO8 have been prepared by heating Na2O2, CaO and ruthenium in closed silver tubes. Silver took part in the reaction. The crystal structure was investigated by X-ray techniques. AgO4Na2.3Ca4.3RuO8 crystallizes with orthorhombic symmetry, space group D192h-Cmmm ; a = 9.255(1), b = 6.683(1), c = 6.696(3) Å , Z = 2. It shows relations to the sodium chloride structure. A statistical distribution of Ag+ and Na+ can be separated in micro space by splitting one oxygen position to give a dumb-bell like O-Ag-O and an octahedral NaO6 coordination.


1994 ◽  
Vol 49 (8) ◽  
pp. 1145-1149 ◽  
Author(s):  
Holger Szillat ◽  
Hanskarl Müller-Buschbaum

Single crystals of Cu0.25Ho1.25W2O8 were prepared by recrystallization from melts and investigated by X-ray diffractometer technique. Cu0.25Ho1.25W2O8 crystallizes with mono­clinic symmetry, space group C2/c, a = 19.123, b = 5.613, c = 11.479 Å, β = 111.44°. Z = 8. It represents a new structure type characterized by W4O18 groups and Cu+/Ho3+ at one point position in statistical distribution. Cu+/Ho3+ show an octahedral coordination. Another point position is occupied by Ho3+ with C. N. = 7.


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 (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.


1996 ◽  
Vol 51 (9) ◽  
pp. 1279-1282 ◽  
Author(s):  
M. Staack ◽  
Hk. Müller-Buschbaum

The copper oxide arsenate Cu4O(AsO4)2 has been prepared and investigated by single crystal X-ray techniques. The compound crystallizes with triclinic symmetry, space group C1i-P1̄, a = 6.4148(7), b = 7.6549(5), c = 8.2241(7) Å, α = 98.52(1), β = 112.39(1), 7 = 98.38(1)°, Z = 2. Cu4O(AsO4)2 is isotypic to Cu4(PO4)2O . Copper ions on one of the four specified sites show nearly planar coordination by O2- and may be assigned to the anionic part of the crystal structure. One of the nine different types of oxygen atoms is coordinated by copper exclusively. The compound is therefore classified as an oxide arsenate.


Sign in / Sign up

Export Citation Format

Share Document