β-CaB4O7: A New Polymorph Synthesized under High-Pressure/High-Temperature Conditions

2003 ◽  
Vol 58 (4) ◽  
pp. 257-265 ◽  
Author(s):  
Hubert Huppertz

A new oxoborate β -CaB4O7 has been synthesized under high-pressure/high-temperature conditions from calcium oxide and boron oxide with a Walker-type multianvil apparatus at 7.7 GPa and 1100 °C. Single crystal X-ray structure determination of β -CaB4O7 revealed: Pmn21, a = 1058.4(1), b = 436.9(1), c = 419.4(1) pm, Z = 2, R1 = 0.0305, wR2 = 0.0587 (all data). The compound is isotypic to the known oxoborates SrB4O7, PbB4O7, and EuB4O7 exhibiting a network structure of linked BO4 tetrahedra. As a prominent feature of the tetrahedral network an oxygen atom is coordinated to three boron atoms. The relation of the crystal structure of the high-pressure phase β -CaB4O7 to the normalpressure phase α-CaB4O7 as well as the relation to the isotypic phases MB4O7 (M = Sr, Pb, Eu) are discussed. The results of IR-spectroscopic investigations on β -CaB4O7 are also presented.

2007 ◽  
Vol 62 (6) ◽  
pp. 759-764 ◽  
Author(s):  
Almut Haberer ◽  
Gunter Heymann ◽  
Hubert Huppertz

The cerium meta-oxoborate δ -Ce(BO2)3 was synthesized under high-pressure / high-temperature conditions of 3.5 GPa and 1050 °C in a Walker-type multianvil apparatus. The crystal structure was determined by single crystal X-ray diffraction data, collected at r. t. The compound crystallizes monoclinicly in the space group P21/c with the lattice parameters a = 422.52(8), b = 1169.7(2), c = 725.2(2) pm, and β = 91.33(3)°. The structure is isotypic to the recently published high-pressure phase δ -La(BO2)3, consisting exclusively of corner sharing [BO4]5− tetrahedra


2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz

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.


2004 ◽  
Vol 59 (2) ◽  
pp. 202-215 ◽  
Author(s):  
Holger Emme ◽  
Tanja Nikelski ◽  
Thomas Schleid ◽  
Rainer Pöttgen ◽  
Manfred Heinrich Möller ◽  
...  

The new orthorhombic meta-oxoborates RE(BO2)3 (≡REB3O6) (RE = Dy-Lu) have been synthesized under high-pressure and high-temperature conditions in a Walker-type multianvil apparatus at 7.5 GPa and 1100 °C. They are isotypic to the known ambient pressure phase Tb(BO2)3, space group Pnma. In contrast to Dy(BO2)3, which was also obtained in small amounts under high-temperature conditions, the preparation of the higher orthorhombic homologues RE(BO2)3 (RE = Ho-Lu) was only possible using high-pressure. The meta-oxoborates RE(BO2)3 (RE = Dy-Er) were synthesized as pure products, whereas the orthorhombic phases with RE = Tm-Lu were only obtained as byproducts. With the exception of Yb(BO2)3 it was possible to establish single crystal data for all compounds. The results of temperature-resolved in-situ powder-diffraction measurements, DTA, IR-spectroscopic investigations, and magnetic properties are also presented.


2017 ◽  
Vol 72 (12) ◽  
pp. 967-975 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz

AbstractNi6B22O39·H2O was synthesized in a high-pressure/high-temperature reaction at 5 GPa/900°C. It crystallizes in the orthorhombic space group Pmn21 (no. 31) with the lattice parameters a=7.664(2), b=8.121(2) and c=17.402(2) Å. The crystal structure is discussed with regard to the isotypic compounds M6B22O39·H2O (M=Fe, Co) and the structurally related phase Cd6B22O39·H2O. Furthermore, the characterization of Ni6B22O39·H2O via X-ray powder diffraction and vibrational spectroscopy is reported.


2010 ◽  
Vol 65 (11) ◽  
pp. 1311-1317 ◽  
Author(s):  
Stephanie C. Neumair ◽  
Reinhard Kaindl ◽  
Hubert Huppertz

The cobalt borate HP-CoB2O4 was synthesized from Co3O4 and B2O3 under high-pressure / high-temperature conditions of 6.5 GPa and 950 °C. The structure of HP-CoB2O4 is isotypic to HPNiB2O4 and β -FeB2O4, representing the third example of a borate, in which every BO4 tetrahedron shares a common edge with a second one. HP-CoB2O4 crystallizes in the space group C2/c (Z = 4) with the parameters a = 934.6(2), b = 562.0(2), c = 443.3(1) pm, β = 108.2(1)°, V = 0.2212(1) nm3, R1 = 0.0218, and wR2 = 0.0410 (all data). The structure consists of layers of BO4 tetrahedra, that are interconnected via strings of edge-sharing FeO6 octahedra


2010 ◽  
Vol 65 (10) ◽  
pp. 1206-1212 ◽  
Author(s):  
Almut Haberer ◽  
Reinhard Kaindl ◽  
Hubert Huppertz

The praseodymium orthoborate λ -PrBO3 was synthesized from Pr6O11, B2O3, and PrF3 under high-pressure / high-temperature conditions of 3 GPa and 800 °C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single-crystal X-ray diffraction data, collected at room temperature. The title compound crystallizes in the orthorhombic aragonite-type structure, space group Pnma, with the lattice parameters a = 577.1(2), b = 506.7(2), c = 813.3(2) pm, and V = 0.2378(2) nm3, with R1 = 0.0400 and wR2 = 0.0495 (all data). Within the trigonal-planar BO3 groups, the average B-O distance is 137.2 pm. The praseodymium atoms are ninefold coordinated by oxygen atoms.


2011 ◽  
Vol 66 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Stephanie C. Neumair ◽  
Johanna S. Knyrim ◽  
Oliver Oeckler ◽  
Reinhard Kaindl ◽  
Hubert Huppertz

The cubic iron hydroxy boracite Fe3B7O13OH・1.5H2O was synthesized from Fe2O3 and B2O3 under high-pressure/high-temperature conditions of 3 GPa and 960 °C in a modified Walker-type multianvil apparatus. The crystal structure was determined at room temperature by X-ray diffraction on single crystals. It crystallizes in the cubic space group F4̄3c (Z = 8) with the parameters a = 1222.4(2) pm, V = 1.826(4) nm3, R1 = 0.0362, and wR2 = 0.0726 (all data). The B-O network is similar to that of other cubic boracites.


2004 ◽  
Vol 3 (6) ◽  
pp. 389-393 ◽  
Author(s):  
Jung-Fu Lin ◽  
Olga Degtyareva ◽  
Charles T. Prewitt ◽  
Przemyslaw Dera ◽  
Nagayoshi Sata ◽  
...  

2008 ◽  
Vol 63 (6) ◽  
pp. 707-712 ◽  
Author(s):  
Johanna S. Knyrim ◽  
Hubert Huppertz

The high-pressure phase β -ZrB2O5 represents the first ternary borate in the system Zr-B-O. The compound was synthesized under high-pressure / high-temperature conditions of 7.5 GPa and 1100 °C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single crystal X-ray diffraction data, collected at room temperature. The monoclinic zirconium borate crystallizes in the space group P21/c with the lattice parameters a = 439.04(9), b = 691.2(2), c = 896.8(2) pm, and β = 90.96(3)°. The structure is isotypic to the high-pressure phase β -HfB2O5, which is built up from layers of exclusively corner-sharing BO4 tetrahedra. Between these layers, the cations are coordinated square-antiprismatically by eight oxygen atoms.


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