Crystal structure of RbBaVO4 and high-pressure modification of KCaVO4

2013 ◽  
Vol 28 (S2) ◽  
pp. S65-S74 ◽  
Author(s):  
N.V. Tarakina ◽  
A.P. Tyutyunnik ◽  
T.V. Dyachkova ◽  
L.L. Surat ◽  
B.V. Slobodin ◽  
...  
Keyword(s):  
High Pressure ◽  
Unit Cell Volume ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Coordination Spheres ◽  
The Difference ◽  
Dense State

The crystal structures of KCaVO4 and RbBaVO4, synthesized at high-pressure/high-temperature and by a conventional solid-state reaction, respectively, were determined using X-ray powder diffraction data. These compounds were found to have the β-K2SO4 structure type (space group Pnma, Z = 4) with parameters a = 7.2628(5) Å, b = 5.7258(4) Å, c = 9.6854(7) Å (KCaVO4), and a = 7.8887(1) Å, b = 5.9589(1) Å, c = 10.3958(2) Å (RbBaVO4). The unit cell volume of KCaVO4, 402.77(5) Å3, is significantly lower than for the low-temperature modification reported previously, 436.2 Å3. The difference can be explained by a pressure-induced phase transition to a more dense state resulting from the rotation of tetrahedra and the exchange of oxygen atoms from the first and second coordination spheres for potassium and calcium atoms.

Synthesis, Structure and Dielectric Properties of Na2SnTeO6

1998 ◽  
Vol 547 ◽  
Author(s):  
J.-H. Park ◽  
P.M. Woodward ◽  
J.B. Parise ◽  
I. Lubomirsky ◽  
O. Stafsudd
Keyword(s):  
Dielectric Constant ◽  
High Pressure ◽  
High Temperature ◽  
Dielectric Properties ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Powder Diffraction Data ◽  
Ambient Conditions ◽  
X Ray ◽  
High Pressure High Temperature

AbstractA new perovskite was recovered from the high pressure-high temperature treatment of the α-TlSbO3 form of Na2SnTeO6 at 7 GPa and 950 °C for 30 minutes. Synchrotron x-ray powder diffraction data show the space group is P21/n with a=5.40361 (5), b=5.46152(5), c=7.69288(7) Å and ß=90.034(3)°. Using disk samples of both polymorphs, the dielectric properties were measured as a function of temperature. At ambient conditions, the perovskite form has a more than 1.5 fold enhancement in dielectric constant compared to the α-TlSbO3 form while the molar volume and the molecular polarizability decrease.

scholarly journals The untypical high-pressure Zintl phase SrGe6

2020 ◽  
Vol 75 (1-2) ◽  
pp. 209-216 ◽  
Author(s):  
Ulrich Schwarz ◽  
Rodrigo Castillo ◽  
Julia M. Hübner ◽  
Aron Wosylus ◽  
Yurii Prots ◽  
...  
Keyword(s):  
High Pressure ◽  
Ambient Pressure ◽  
Three Dimensional ◽  
Structure Type ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Quantum Chemical Analysis ◽  
Electronic Density ◽  
X Ray ◽  
High Pressure High Temperature

AbstractThe binary strontium germanide SrGe6 was synthesized at high-pressure high-temperature conditions of approximately 10 GPa and typically 1400 K before quenching to ambient conditions. At ambient pressure, SrGe6 decomposes in a monotropic fashion at T = 680(10) K into SrGe2 and Ge, indicating its metastable character. Single-crystal X-ray diffraction data indicate that the compound SrGe6 adopts a new monoclinic structure type comprising a unique three-dimensional framework of germanium atoms with unusual cages hosting the strontium cations. Quantum chemical analysis of the chemical bonding shows that the framework consists of three- and four- bonded germanium atoms yielding the precise electron count Sr[(4bGe0]4[(3b)Ge−]2 in accordance with the 8 − N rule and the Zintl concept. Conflicting with that, a pseudo-gap in the electronic density of states appears clearly below the Fermi level, and elaborate bonding analysis reveals additional Sr–Ge interactions in the concave coordination polyhedron of the strontium atoms.

scholarly journals Al5B12O25(OH) and Ga4InB12O25(OH) – two additional triel borates with the structure type M5B12O25(OH) (M = Ga, In)

2020 ◽  
Vol 75 (6-7) ◽  
pp. 605-613
Author(s):  
Daniela Vitzthum ◽  
Daniel S. Wimmer ◽  
Ingo Widmann ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Ir Spectroscopy ◽  
Single Crystal ◽  
Crystal Structures ◽  
Structure Type ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature

AbstractThe isotypic triel borates Al5B12O25(OH) and Ga4InB12O25(OH) were synthesized in a Walker-type multianvil apparatus under high-pressure/high-temperature conditions of 12.0 GPa/1400 °C and 12.3 GPa/1200 °C, respectively. The crystal structures of both compounds, determined by single-crystal X-ray diffraction, constitute new representatives of the structure type M5B12O25(OH) (M = Ga, In) crystallizing in the space group I41/acd. The presence of the hydroxyl groups was confirmed via single-crystal IR spectroscopy.

Crystal structure of moganite-type phosphorus oxynitride: relationship to other twinned-quartz-based structures

1999 ◽  
Vol 55 (5) ◽  
pp. 677-682 ◽  
Author(s):  
J. Haines ◽  
C. Chateau ◽  
J. M. Léger ◽  
A. Le Sauze ◽  
N. Diot ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Structure Type ◽  
Neutron Powder Diffraction ◽  
Powder Diffraction Data ◽  
Monoclinic Form ◽  
Neutron Powder Diffraction Data ◽  
Intermediate Phases ◽  
High Pressure High Temperature

The structure of moganite-type phosphorus oxynitride quenched from high-pressure high-temperature conditions has been refined using neutron powder diffraction data. This moganite-type structure, space group I2/a, Z = 12, is slightly less distorted with respect to the Imab aristotype than is moganite (a monoclinic form of silica). A close topological relationship has been identified between the moganite-type and orthorhombic BeH2 structures indicating that SiO2, PON and BeH2 all adopt structures belonging to the twinned-quartz-based group. This group represents another possible structure type for systems composed of corner-sharing AX 4 tetrahedra. Structures of this group are obvious candidates for intermediate phases between the cristobalite and quartz types.

High-Pressure Preparation, Crystal Structure, and Properties of RE4B6O15 (RE = Dy, Ho) with an Extension of the “Fundamental Building Block”-Descriptors

2003 ◽  
Vol 58 (4) ◽  
pp. 278-290 ◽  
Author(s):  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
Building Block ◽  
Structure Type ◽  
Structure And Properties ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Fundamental Building Block ◽  
High Pressure High Temperature

High-pressure/high-temperature conditions of 8 GPa and 1000°C were used to synthesizethe new rare earth oxoborates RE4B6O15 (RE = Dy, Ho) in a Walker-type multianvil apparatus.The single crystal X-ray structure determination of Ho4B6O15 revealed the followingdata: C2/c, a = 1164.1(1), b = 436.7(1), c = 1882.5(1) pm, β = 96.71(1)°, Z = 4, R1 = 0.0291, wR2 = 0.0505 (all data). The two isotypic compounds exhibit a new structure type built up from corrugated layers of BO4 tetrahedra. In contrast to all known oxoborates the linkingof the BO4 tetrahedra is partially realized via common edges. Regarding the “fundamentalbuilding block”-concept, we introduce a new descriptor “” for edge-sharing BO4 tetrahedra.Temperature-resolved in situ powder diffraction measurements and IR/Raman-spectroscopicinvestigations on Dy4B6O15 are also reported.

scholarly journals High-pressure synthesis and crystal structure of the mixed-cation borate Ga4In4B15O33(OH)3

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Mixed Cation ◽  
High Pressure High Temperature ◽  
Pressure Synthesis

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.

scholarly journals High-pressure synthesis and characterization of the non-centrosymmetric scandium borate ScB6O9(OH)3

2020 ◽  
Vol 75 (6-7) ◽  
pp. 597-603
Author(s):  
Birgit Fuchs ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Structure Solution ◽  
Temperature Experiment ◽  
Pressure Synthesis

AbstractThe non-centrosymmetric scandium borate ScB6O9(OH)3 was obtained through a high-pressure/high-temperature experiment at 6 GPa and 1473 K. Single-crystal X-ray diffraction revealed that the structure is isotypic to InB6O9(OH)3 containing borate triple layers separated by scandium layers. The compound crystallizes in the space group Fdd2 with the lattice parameters a = 38.935(4), b = 4.4136(4), and c = 7.6342(6) Å. Powder X-ray diffraction and vibrational spectroscopy were used to further characterize the compound and verify the proposed structure solution.

The high-pressure cadmium borate Cd6B22O39·H2O

2015 ◽  
Vol 70 (3) ◽  
pp. 183-190 ◽  
Author(s):  
Gerhard Sohr ◽  
Nina Ciaghi ◽  
Klaus Wurst ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Cell Dimensions ◽  
Temperature Experiment ◽  
Unit Cell Dimensions ◽  
Ir And Raman

AbstractSingle crystals of the hydrous cadmium borate Cd6B22O39·H2O were obtained through a high-pressure/high-temperature experiment at 4.7 GPa and 1000 °C using a Walker-type multianvil apparatus. CdO and partially hydrolyzed B2O3 were used as starting materials. A single crystal X-ray diffraction study has revealed that the structure of Cd6B22O39·H2O is similar to that of the type M6B22O39·H2O (M=Fe, Co). Layers of corner-sharing BO4 groups are interconnected by BO3 groups to form channels containing the metal cations, which are six- and eight-fold coordinated by oxygen atoms. The compound crystallizes in the space group Pnma (no. 62) [R1=0.0379, wR2=0.0552 (all data)] with the unit cell dimensions a=1837.79(5), b=777.92(2), c=819.08(3) pm, and V=1171.00(6) Å3. The IR and Raman spectra reflect the structural characteristics of Cd6B22O39·H2O.

X-ray powder diffraction data for tetrazene nitrate monohydrate, C2H9N11O4

2021 ◽  
pp. 1-3
Author(s):  
J. Maixner ◽  
J. Ryšavý
Keyword(s):  
Cell Volume ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

X-ray powder diffraction data, unit-cell parameters, and space group for tetrazene nitrate monohydrate, C2H9N11O4, are reported [a = 5.205(1) Å, b = 13.932(3) Å, c = 14.196(4) Å, β = 97.826(3)°, unit-cell volume V = 1019.8(4) Å3, Z = 4, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurities were observed.

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