scholarly journals Notizen:Über NaBa3RuO6und NaBa3IrO6.Zwei Edelmetall-Oxometallate mit Sr4PtO6-Struktur / On NaBa3RuO6and NaBa3IrO6.Two Noble Metal Oxometallates Showing Sr4PtO6Structure

1996 ◽  
Vol 51 (8) ◽  
pp. 1204-1206 ◽  
Author(s):  
S. Frenzen ◽  
Hk. Müller-Buschbaum

Single crystals of NaBa3RuO6 (I) and NaBa3IrO6 (II) have been prepared by crystallization from melts in closed silver tubes. The crystal structures were investigated by X-ray techniques. Both compounds crystallize with trigonal (rhombohedral) symmetry, space group D63d-R3̅c, I: a = 10.107(2), c = 11.872(2) Å, II: a = 10.128(2), c = 11.905(2) Å, Z = 6. I and II are isostructural to the Sr4PtO6 type.

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 (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.


1995 ◽  
Vol 50 (4) ◽  
pp. 581-584 ◽  
Author(s):  
S. Frenzen ◽  
Hk. Müller-Buschbaum

Single crystals of NaSr3RuO6 have been prepared in closed silver tubes and investigated by X-ray techniques. This compound crystallizes with trigonal (rhombohedral) symmetry, space group D63d - R3̅c , a = 9.6069(8), c = 11.513(2) Å, Z = 6, and is isotypic to compounds of the Sr4PtO6 type. The crystal structure is discussed with respect to related compounds with partial replacement of alkaline earth elem ents by sodium and copper.


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.


1997 ◽  
Vol 52 (7) ◽  
pp. 785-789 ◽  
Author(s):  
R. Rettich ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of Ba(Ca0.6Mn0.4)V2O7 have been prepared by crystallization from melts. X-ray investigations revealed a new quaternary vanadium oxide of the type BaMV2O7. The M positions are occupied statistically by Ca2+ and Mn2+. The compound crystallizes with orthorhombic symmetry, space group D2h16-Pnma, a = 15.429(2), b - 5.7005(12), c = 7.364(2) Å, Z = 4. The crystal structure can be interpreted as a [Ba(Ca,Mn)O6] network with incorporated V-O- V groups. Considering the nearest O2- neighbours of the incorporated vanadium, the V-O-V groups are complemented to give V2O7 divanadate units. Ba(Ca0.6Mn0.4)V2O7 is isotypic to BaMV2O7 (M=Ca,Cd) but not to BaMnV2O7.


1995 ◽  
Vol 50 (6) ◽  
pp. 871-874 ◽  
Author(s):  
J. Feldmann ◽  
S. Münchau ◽  
Hk. Müller-Buschbaum

Single crystals of CuCdVO4 have been prepared by CO2-LASER techniques. X -ray investigations of the black single crystals led to orthorhombic symmetry, space group D2h17-Cmcm , a = 5.921(1), b = 9.065(4), c = 6.633(2) Å, Z = 4. CuCdVO4 represents the first example of a quaternary oxide containing cadmium and copper(I). Compared to AgCdVO4, CuCdVO4 shows a different linkage of the VO4 and CuO4 tetrahedra, explaining the missing isotypy of these com pounds.


1997 ◽  
Vol 52 (5) ◽  
pp. 639-642 ◽  
Author(s):  
B. Mertens ◽  
Hk. Müller-Buschbaum

Abstract Single crystals of KCd0,67Cu4,33V3O13 (I), RbCd0,5Cu4,5V3O13 (II) and TlCd0,5Cu4,5V3O13 (III) have been prepared by crystallization from melts. X-ray analysis led to monoclinic symmetry, space group C22h-P21/m (Nr. 11) and the lattice constants (I) - (III): a = 10.728(1), 10.746(3), 10.746(3), b = 6.155(1), 6 .163(2), 6.175(2), c = 8.363(2), 8.350(2), 8.337(3) Å , β = 97.69(2), 97.73(2), 97.61(5)°, Z = 2. The crystal structures are isotypic to the BaMg2CU8V6 O26 type. Cu2+ occurs in square pyramidal and unusual trigonal bipyram idal coordination by oxygen . The MgO6 octahedra of the aristo type BaMg2Cu8V6O26 are statisti­cally occupied by cadmium and copper. The distortion of the (Cd /Cu)O6 octahedra is discus­sed with respect to the polyhedra network.


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.


1996 ◽  
Vol 51 (10) ◽  
pp. 1407-1410 ◽  
Author(s):  
B. Wedel ◽  
Hk. Müller-Buschbaum

Single crystals of Ba2Nb2TeO10) have been prepared by solid state reactions in air. X-ray investigations led to orthorhombic symmetry, space group D152h-Pbca, a = 7.242(4), b = 12.433(3), c = 9.932(3) Å. Z = 4. Nb5+ and Te6+ show octahedral coordination by O2- . The crystal structure is characterized by planes of edge- and corner-sharing NbO6- and TeO6octahedra. It is shown that in spite of nearly identical lattice constants of Ba2Nb2TeO10 with compounds of the composition M0,5BaNbTe2O9 the so far unknown crystals of these substances may not be derived from the Ba2Nb2TeO10 type.


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