Die Synthese und Kristallstruktur von cobalthaltigen Boratoxiden: Co1,5Ti0,5(BO3)O und Co1,5Zr0,5(BO3)O / Synthesis and Crystal Structure of Cobalt Containing Borate Oxides: Co1.5Ti0.5(BO3)O and Co1.5Zr0.5(BO3)O

1995 ◽  
Vol 50 (11) ◽  
pp. 1653-1657 ◽  
Author(s):  
Anne Utzolino ◽  
Karsten Bluhm

Single crystals of Co1.5Ti0.5(BO3)O (I) and Co1.5Zr0.5(BO3)O (II) were obtained by a B2O3 flux technique. Both compounds crystallize with orthorhombic symmetry, space group D162h-Pnma (Nr. 62), I a = 928.1; b = 311.1; c = 940.1 pm; Z = 4 and II a = 949.5; b = 323.42; c = 934.7 pm; Z = 4. The compounds are isotypic to the mineral warwickite. All metal ions are octahedrally coordinated by oxygen ions. The structure contains isolated, trigonal planar BO3 units and oxygen that is not coordinated to boron.

1995 ◽  
Vol 50 (8) ◽  
pp. 1146-1150 ◽  
Author(s):  
Anne Utzolino ◽  
Karsten Bluhm

Single crystals of the compounds MnFe(BO3)O (I) and MnAl0.5Y0.5(BO3)O (II), were obtained by a B2O3 flux technique. I crystallizes with orthorhombic symmetry, space group D162h -Pnma (Nr.62), a = 939.92; b = 319.41; c = 939.11 pm; Z = 4 and II with monoclinic symmetry, space group C52h-P21/n (Nr. 14). a = 325.6; b = 955.1; c = 929.2 pm; β = 90.70° ; Z = 4. I is isotypic to the mineral Warwickite, while II is a distorded variant of this structure. All metal ions are octahedrally coordinated. Both structures contain isolated, trigonal planar BO3 units and oxygen atoms that are not coordinated to boron.


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.


1996 ◽  
Vol 51 (2) ◽  
pp. 240-244
Author(s):  
Hk. Müller-Buschbaum ◽  
St. Gallinat

Abstract Single crystals of (I) CuDyMo2O8 and (II) CuYbMo2O8 have been prepared by crystalli­sation from melts. Both com pounds crystallize with orthorhombic symmetry, space group D152h-Pbca with (I): a = 10.195(1), b = 9.721(2), c = 14.563(3); (II): a = 10.094(6), b = 9.628(9), c = 14.467(8) Å, Z = 8. The crystal structure is characterized by a triangular CuO3-polygon, a square antiprismatic coordination around the Rare Earth ions and the typical Mo O4 tetra­ hedra.


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 (1) ◽  
pp. 90-94 ◽  
Author(s):  
O. Sedello ◽  
Hk. Müller-Buschbaum

Single crystals of (Cu,Fe)3,63Mo3O12 have been prepared by crystallisation from melts. X-ray investigations lead to orthorhombic symmetry, space group D24-P212121, a = 5.0952(8), b = 10.637(2), c = 17.881(3) Å, Z = 4. (Cu,Fe)3,63Mo3O12 is isotypic to Cu3,85Mo3O12 or (Cu,Zn)3,75Mo3O12. Molybdenum shows tetrahedral coordination by oxygen. Cu+ and Fe2+ are probably distributed statistically over four different point positions. Interesting features of the crystal structure are one-dimensional chains of face shared (Cu,Fe)O6 octahedra.


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.


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.


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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