Synthese and Krystalchemie der β-Form eines gemischten Zinkorthoarsenats: Zn2,28Mg0,72(AsO4)2 / Synthesis and Crystal Chemistry of the β-Form of a Mixed Zinc Orthoarsenate: Zn2.28Mg0.72(AsO4)2

1996 ◽  
Vol 51 (4) ◽  
pp. 469-472 ◽  
Author(s):  
D. Frerichs ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Single Crystals ◽  
Crystal Chemistry ◽  
Lattice Parameters ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
Laser Techniques ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of Zn2.28Mg0.72(AsO4)2 have been prepared by CO2 LASER techniques. The compound crystallizes with monoclinic symmetry space group C52h-P21/n and the lattice parameters a = 5.292(2), b = 8.450(3), c = 7.737(3) Å , β = 96.33(3)°, Z = 2. Zn2.28Mg0.72(AsO4)2 is isotypic to β-Zn3(AsO4)2. The formation of the β-Zn3(AsO4)2 struc­ture instead of other possible orthoarsenates is discussed.

Zwei Beispiele fiir partielle und totale Defekte im Ba▪Ln2Mo4O16-Typ: BaCu0,41▪0,59Pr2Mo4O16 und Ba▪Yb2Mo4O16 / Two Examples of Partial and Total Defects in the Ba▪Ln2Mo4O16-Typ: BaCu0,41▪0,59Pr2Mo4O16 and Ba▪Yb2Mo4O16

1996 ◽  
Vol 51 (1) ◽  
pp. 85-89 ◽  
Author(s):  
St. Gallinat ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Reference Compound ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
First Case ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of (I) BaCu0,41Pr2Mo4O16 and (II) BaYb2Mo4O16 have been prepared by flux technique. Both compounds crystallize with monoclinic symmetry, space group C62h-C2/c with (I): a = 5.352(11), b = 12.888(2), c = 19.399(4) Å; β = 90.89(3)°; (II): a = 5.181(7), b = 12.467(3), c -19.350(3) Å , β -91.93(2)°, Z = 4. The crystal structure is characterized by 1∞[BaMO12]-chains along [010]. In the first case the M positions are occupied by copper by about 41%, in the second case these positions remain completely unoccupied. With respect to the crystal chemistry of the reference compound Ba(Cu0.22Mg0,78)Nd2Mo4O16 all substances of the composition BaLn2Mo4O16 should be written as Ba▪Ln2Mo4O16 indicating the holes in the 1∞[BaMO12]-chains by ▪.

Zur Kristallchemie eines Natrium-Cadmium-Oxoiridats: Na3Cd2IrO6 / On the Crystal Chemistry of a Sodium Cadmium Oxoiridate: Na3Cd2IrO6

1996 ◽  
Vol 51 (6) ◽  
pp. 822-825 ◽  
Author(s):  
S. Frenzen ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Sodium Chloride ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
X Ray ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of Na3Cd2IrO6 have been prepared by crystallization from melts in closed silver tubes. The crystal structure was investigated by X-ray techniques. Na3Cd2IrO6, crystallizes with monoclinic symmetry, space group C32h-C2/m; a = 5.663(2), b = 9.783(3), c = 5.689(2) Å, β = 109.95(2)°, Z = 2. It is isotypic to M+5A7+O6 (M = Li, Na; A = Re, Os) and shows relations to the sodium chloride structure in spite of an ordered distribution of Na+, Cd2+ and Ir5+

Eine synthetische Spezies zum Mineral Howardevansit mit Eisen anstelle von Kupfer: NaFe3V3O12 / A Synthetic Species of the Mineral Howardevansite with Copper Displacing Iron: NaFe3V3O12

1995 ◽  
Vol 50 (1) ◽  
pp. 51-55 ◽  
Author(s):  
F.-D. Martin ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Solid State ◽  
Melting Point ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Solid State Reaction ◽  
Space Group ◽  
Triclinic Symmetry ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of NaFe3V3O12 have been prepared by solid state reaction below the melting point of the reaction mixture. This compound is isotypic to the mineral Howardevansite but shows lower triclinic symmetry, space group C11–P1, a = 6.757(2), b = 8.155(2), c = 9.816(3) Å, α = 106.05(2), β = 104.401(9), γ = 102.09(2)°, Z = 2. The acentric space group is caused by the sodium positions, all other atoms comply with the space group P̄ of Howardevansite. The different ions are coordinated by O2- forming VO4 tetrahedra, FeO6 octahedra, trigonal FeO5 bipyramids and irregular NaO5 and NaO7 polyhedra, respectively. The crystal chemistry is discussed with respect to Howardevansite.

Über das Oxomolybdat AgKCu3Mo4O16 mit Silber in siebenfacher Koordination / About the Oxomolybdate AgKCu3Mo4O16 with Silver in Seven-Fold Coordination

1995 ◽  
Vol 50 (2) ◽  
pp. 252-256 ◽  
Author(s):  
H. Szillat ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
X Ray ◽  
Silver Copper ◽  
Symmetry Space ◽  
Symmetry Space Group

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.

Ein Beitrag zur Kristallchemie von Verbindungen mit Johillerit-Struktur: KCo3Cu(As2,58V0,42)O12 / On the Crystal Chemistry of Compounds with Johillerite Structure: KCo3Cu(As2,58V0,42)O12

1994 ◽  
Vol 49 (11) ◽  
pp. 1463-1466 ◽  
Author(s):  
D. Frerichs ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Solid State ◽  
Melting Point ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Structure Type ◽  
Solid State Reactions ◽  
Tetrahedral Coordination ◽  
Monoclinic Symmetry ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of KCo3Cu(As2.58V0.42)O12 were prepared by solid state reactions below the melting point of the reaction mixture (K2CO3, CuO, COC2O4, V2O5 and 3 As2O5 · 5H2O). It crystallizes with monoclinic symmetry, space group C62h-C2/c, a = 12.207, b = 12.730, c = 6.811 Å, β = 113.69°, Z = 4. The structure type is characterized by isolated twisted-square CuO4-polygons, CoO6-octahedra and a special 4+4-coordination of the potassium ion. As5+ and V5+ are in tetrahedral coordination with a partly statistical distribution of these ions.

Zur Synthese und Kristallstruktur von manganhaltigen Boratoxiden: MnFe(BO3)O und MnAl0,5Yo,5(BO3)O / Synthesis and Crystal Structure of Manganese Borate Oxides: MnFe(BO3)O and MnAl0,5Yo,5(BO3)O

1995 ◽  
Vol 50 (8) ◽  
pp. 1146-1150 ◽  
Author(s):  
Anne Utzolino ◽  
Karsten Bluhm
Keyword(s):  
Crystal Structure ◽  
Metal Ions ◽  
Single Crystals ◽  
Orthorhombic Symmetry ◽  
Monoclinic Symmetry ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

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.

Hochtemperatursynthese und Kristallchemie der Oxotantalate Cr2+0,761Ta2,095O6 und FeTa2O6 / High Temperature Synthesis and Crystal Chemistry of the Oxotantalates Cr2+0,761Ta2,095O6 and FeTa2O6

1995 ◽  
Vol 50 (5) ◽  
pp. 712-716 ◽  
Author(s):  
E. Peters ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Monoclinic Symmetry ◽  
Temperature Synthesis ◽  
Space Group ◽  
High Temperature Synthesis ◽  
Laser Techniques ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Black single crystals of Cr0.761Ta2.095O6 have been prepared by CO2-LASER techniques. This phase crystallizes with monoclinic symmetry, space group C52h-P21/c, a = 4.748(1). b = 4.750(2), c = 10.405(3) Å, β = 117.152(13)°, Z = 2. The crystal structure is closely related to the trirutile type, although the metal positions are partly statistically occupied by Cr2+ and Ta5+ or underoccupied by Ta5+, respectively. FeTa2O6, prepared by the same m ethod does neither show any statistic occupation nor deviations from the trirutile structure, space group D144h-P42/mnm, a = 4.7595(5) Å, c = 9.201(2)A, Z = 2 .

Isolierte 1∞[TeO5]-Oktaederketten im Bleitellurat Pb2TeO5 / Isolated 1∞[TeO5] Chains of Octahedra in the Lead Tellurate Pb2TeO5

1998 ◽  
Vol 53 (3) ◽  
pp. 287-290 ◽  
Author(s):  
B. Wedel ◽  
L. Wulff ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Lone Pair ◽  
Lattice Energy ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
X Ray ◽  
Symmetry Space ◽  
Symmetry Space Group

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.

scholarly journals Notiz zur Kristallchemie von LiBa2Cu3O6 / Note on the Crystal Chemistry of LiBa2Cu3O6

1995 ◽  
Vol 50 (4) ◽  
pp. 681-683 ◽  
Author(s):  
G. Tams ◽  
Hk. Müller-Buschbaum ◽  
Ch. Lang
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Laser Heating ◽  
Space Group ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of LiBa2Cu3O6 have been prepared by recrystallization from melts in a stream of dry Argon as well as by spontaneous CO2- LASER heating. It crystallizes with orthorhom bic symmetry, space group D232h - Fmmm, a = 8,219(2), b = 11,520 (2), c = 14,284(3) Å, Z = 8. The crystal structure is isotypic to NaBa2Cu3O6.

Zur Kristallchemie eines Silber-Cadmium-Oxovanadats: AgCdVO4 / On the Crystal Chemistry of a Silver Cadmium Oxovanadate: AgCdVO4

1995 ◽  
Vol 50 (5) ◽  
pp. 703-706 ◽  
Author(s):  
S. Münchau ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Single Crystals ◽  
Crystal Chemistry ◽  
Orthorhombic Symmetry ◽  
Space Group ◽  
Olivine Structure ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group ◽  
Light Orange

Abstract Single crystals of AgCdVO4 have been prepared in closed silver tubes using V2O5 as a flux. The light-orange crystals show orthorhombic symmetry, space group D162h-Pnma, a = 9.786(2), b = 6.994(1), c = 5.439(1) Å, Z = 4. The hitherto unknown AgCdVO4 is related to the Olivine structure but isotypic to Ag2CrO4 and NaCd4(VO4)3 respectively. The differences in crystal chemistry between the Olivine type, NaCd4(VO4)3 and AgCdVO4 are discussed.

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