High-pressure / High-temperature Studies on the Stannides RENiSn (RE = Ce, Pr, Nd, Sm) and REPdSn (RE = La, Pr, Nd)

2008 ◽  
Vol 63 (6) ◽  
pp. 695-706 ◽  
Author(s):  
Jan F. Riecken ◽  
Gunter Heymann ◽  
Wilfried Hermes ◽  
Ute Ch. Rodewald ◽  
Rolf-Dieter Hoffmann ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Magnetic Moments ◽  
Structural Data ◽  
Normal Pressure ◽  
Space Group ◽  
Type Space ◽  
High Pressure Phase Transition ◽  
High Pressure High Temperature ◽  
Rare Earth Coordination

The normal-pressure (NP) orthorhombic TiNiSi-type (space group Pnma) stannides RENiSn (RE = Ce, Pr, Nd, Sm) and REPdSn (RE = La, Pr, Nd) were transformed into the corresponding hexagonal ZrNiAl-type (space group P6̄2m) high-pressure (HP) modifications under multianvil high-pressure (7.5 - 11.5 GPa) high-temperature (1100 - 1200 °C) conditions. The structures of NP-CeNiSn, HPPrNiSn, NP-NdNiSn, HP-LaPdSn, HP-PrPdSn, and HP-NdPdSn were refined from single crystal X-ray diffractometer data. Structural data for HP-SmNiSn were obtained from a Rietveld powder refinement. The high-pressure phase transition significantly changes the rare earth coordination, i. e. 4 RE + 6 Ni(Pd) + 6 Sn atoms for the NP-phases and 6 RE + 5 Ni(Pd) + 6 Sn atoms for the HPphases. Susceptibility measurements of HP-PrPdSn and HP-NdPdSn reveal paramagnetic behavior with experimental magnetic moments of 3.61(1) μB/Pr atom and 3.66(1) μB/Nd atom, respectively. Low-temperature susceptibility and specific heat data point to inhomogeneous magnetism and spinglass behavior, respectively.

scholarly journals Multianvil High-Pressure/High-Temperature Synthesis and Characterization of multiferroic HP-Co3TeO6

2021 ◽  
Author(s):  
Gunter Heymann ◽  
Elisabeth Selb ◽  
Toni Buttlar ◽  
Oliver Janka ◽  
Martina Tribus ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Type Structure ◽  
Synthesis And Characterization ◽  
Temperature Synthesis ◽  
Space Group ◽  
Crystal System ◽  
High Temperature Synthesis ◽  
High Pressure High Temperature

By high-pressure/high-temperature multianvil synthesis a new high-pressure (HP) phase of Co3TeO6 was obtained. The compound crystallizes in the acentric trigonal crystal system of the Ni3TeO6-type structure with space group R3...

scholarly journals High-Pressure Synthesis, Crystal Structure, and Photoluminescence Properties of β-Y2B4O9:Eu3+

Inorganics ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 136
Author(s):  
Fuchs ◽  
Schröder ◽  
Heymann ◽  
Jüstel ◽  
Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Photoluminescence Properties ◽  
Triclinic Space Group ◽  
Space Group ◽  
High Pressure High Temperature ◽  
Temperature Experiment ◽  
Pressure Synthesis

A high-pressure/high-temperature experiment at 7.5 GPa and 1673 K led to the formation of the new compound βY2B4O9. In contrast to the already known polymorph αY2B4O9, which crystallizes in the space group C2/c, the reported structure could be solved via single-crystal Xray diffraction in the triclinic space group P1 (no. 2) and is isotypic to the already known lanthanide borates βDy2B4O9 and βGd2B4O9. Furthermore, the photoluminescence of an europium doped sample of βY2B4O9:Eu3+ (8%) was investigated.

Synthesis and Crystal Structure of the High-pressure Cobalt Borate HP-CoB2O4

2010 ◽  
Vol 65 (11) ◽  
pp. 1311-1317 ◽  
Author(s):  
Stephanie C. Neumair ◽  
Reinhard Kaindl ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Common Edge ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
The Third ◽  
Temperature Conditions ◽  
High Pressure High Temperature

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

High-pressure syntheses and crystal structures of orthorhombic DyGaO3 and trigonal GaBO3

2015 ◽  
Vol 70 (4) ◽  
pp. 207-214 ◽  
Author(s):  
Daniela Vitzthum ◽  
Stefanie A. Hering ◽  
Lukas Perfler ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Crystal Structures ◽  
Diffraction Data ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
High Pressure High Temperature

AbstractOrthorhombic dysprosium orthogallate DyGaO3 and trigonal gallium orthoborate GaBO3 were synthesized in a Walker-type multianvil apparatus under high-pressure/high-temperature conditions of 8.5 GPa/1350 °C and 8 GPa/700 °C, respectively. Both crystal structures could be determined by single-crystal X-ray diffraction data collected at room temperature. The orthorhombic dysprosium orthogallate crystallizes in the space group Pnma (Z = 4) with the parameters a = 552.6(2), b = 754.5(2), c = 527.7(2) pm, V = 0.22002(8) nm3, R1 = 0.0309, and wR2 = 0.0662 (all data) and the trigonal compound GaBO3 in the space group R3̅c (Z = 6) with the parameters a = 457.10(6), c = 1419.2(3) pm, V = 0.25681(7) nm3, R1 = 0.0147, and wR2 = 0.0356 (all data).

Notizen: Sodium Metaperrhenate, NaReO4: High Pressure Synthesis of Single Crystals and Structure Refinement

1995 ◽  
Vol 50 (9) ◽  
pp. 1417-1418 ◽  
Author(s):  
Alexandra Atzesdorfer ◽  
Klaus-Jürgen Range
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystals ◽  
Sodium Nitrate ◽  
Structure Refinement ◽  
Type Structure ◽  
Space Group ◽  
High Pressure Synthesis ◽  
High Pressure High Temperature ◽  
Pressure Synthesis

Single crystals of sodium metaperrhenate, NaReO4, have been obtained by oxidation of rhenium metal with sodium nitrate under high pressure- high temperature conditions (modified Belttype apparatus, 4 kbar, 400 °C, Au-capsules). The crystals are tetragonal, space group I41/a, with a = 5.3654(4), c = 11.732(2) Å and Z = 4. The structure was refined to R - 0.026, Rw = 0.013 for 382 unique, absorption-corrected reflections. The scheelite-type structure for NaReO4, proposed by Beintema in 1937, could be confirmed. It consists of isolated ReO4 tetrahedra (Re-O= 1.728(2) Å ), connected by NaOs dodecahedra (<Na- O > = 2.582(2) Å).

scholarly journals Single-Crystal Structure of HP-Sc2TeO6 Prepared by High-Pressure/High-Temperature Synthesis

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1554
Author(s):  
Raimund Ziegler ◽  
Martina Tribus ◽  
Clivia Hejny ◽  
Gunter Heymann
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Ambient Pressure ◽  
Normal Pressure ◽  
Monoclinic Space Group ◽  
Temperature Synthesis ◽  
X Ray ◽  
High Temperature Synthesis ◽  
High Pressure High Temperature

The first high-pressure scandium tellurate HP-Sc2TeO6 was synthesized from an NP-Sc2TeO6 normal-pressure precursor at 12 GPa and 1173 K using a multianvil apparatus (1000 t press, Walker-type module). The compound crystallizes in the monoclinic space group P2/c (no. 13) with a = 729.43(3), b = 512.52(2), c = 1095.02(4) pm and β = 103.88(1)°. The structure was refined from X-ray single-crystal diffractometer data: R1 = 0.0261, wR2 = 0.0344, 568 F2 values and 84 variables. HP-Sc2TeO6 is isostructural to Yb2WO6 and is built up from TeO6 octahedra, typical for tellurate(VI) compounds. During synthesis, a reconstructive transition from P321 (normal-pressure modification) to P2/c (high-pressure modification) takes place and the scandium–oxygen distances as well as the coordination number of scandium increase. However, the coordination sphere around the Te6+ cations gets only slightly distorted. High-temperature powder XRD investigations revealed a back-transformation of HP-Sc2TeO6 to the ambient-pressure modification above 973 K.

scholarly journals Kristallstruktur von SrGe2 bei hohen Drücken / Crystal Structure of SrGe2 at High Pressures

1979 ◽  
Vol 34 (3) ◽  
pp. 524 ◽  
Author(s):  
Jürgen Evers ◽  
Gilbert Oehlinger ◽  
Armin Weiss
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
High Pressures ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Space Group ◽  
High Pressure High Temperature

Abstract After a high pressure -high temperature treatment of orthorhombic SrGe2 (BaSi2 type of structure) a trigonal polymorph (EuGe2 type of structure) is obtained: space group P3̄m 1; a - 410.4 pm, c - 516.5 pm; Z - 1; zGe = 0.406.

High-pressure Syntheses and Crystal Structures of Monoclinic B-Ho2O3 and Orthorhombic HoGaO3

2009 ◽  
Vol 64 (9) ◽  
pp. 1032-1040 ◽  
Author(s):  
Stefanie A. Hering ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Crystal Structures ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Temperature Conditions ◽  
High Pressure High Temperature

Monoclinic holmium sesquioxide B-Ho2O3 and orthorhombic holmium orthogallate HoGaO3 were synthesized in a Walker-type multianvil apparatus under high-pressure / high-temperature conditions of 11.5 GPa / 1250 °C and 7.5 GPa / 1250 °C, respectively. Both crystal structures could be determined by single-crystal X-ray diffraction data, collected at r. t. The monoclinic holmium oxide crystallizes in the space group C2/m (Z = 6) with the parameters a = 1394.7(3), b = 350.83(7), c = 865.6(2) pm, β = 100.23(3)°, R1 = 0.0517, wR2 = 0.1130 (all data), and the orthorhombic compound HoGaO3 in Pnma (Z = 4) with the parameters a = 553.0(2), b = 753.6(2), c = 525.4(2) pm, R1 = 0.0222, and wR2 = 0.0303 (all data).

High-pressure – High-temperature Synthesis of Na6MnO4

2009 ◽  
Vol 64 (5) ◽  
pp. 487-490 ◽  
Author(s):  
Steffen Pfeiffer ◽  
Martin Jansen
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Rietveld Refinement ◽  
Title Compound ◽  
Temperature Synthesis ◽  
Hexagonal System ◽  
Space Group ◽  
X Ray ◽  
High Temperature Synthesis ◽  
High Pressure High Temperature

The title compound has been synthesized under 4 GPa and at 500 ◦C from Na2O andMnO as starting materials. Rietveld refinement of the X-ray powder pattern indicates that Na6MnO4 is isostructural to Na6ZnO4 and thus is representing the second manifestation of an “isolated” [MnO4]6− anion after Na14Mn2O9. The compound crystallizes in the hexagonal system in space group P63mc (no. 186) with a = 7.6631(2) and c = 5.9013(2) ° A, V = 300.1 °A3, and Z = 2.

Einkristalldaten der Hochdruck- Hochtemperaturphase von BaGe2 / Structural Refinement of the High Pressure - High Temperature Phase of BaGe2

1980 ◽  
Vol 35 (3) ◽  
pp. 397-398 ◽  
Author(s):  
Jürgen Evers ◽  
Gilbert Oehlinger ◽  
Armin Weiss
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Structural Analysis ◽  
Single Crystal ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Structural Refinement ◽  
Space Group ◽  
High Pressure High Temperature

A single crystal investigation of the high pressure - high temperature phase of BaGe2 (α-ThSi2 type of structure) has been performed. Space group I41/amd has been derived from rotation, Weissenberg and precession photographs. On a four-circle-diffractometer 1082 reflections with 0 ≤ h ≤ 8, 0 ≤ fc ≤ 8, 2̅4̅ ≤ l ≤ 24 have been measured with filtered Mo-radiation. This results in 296 independent reflections. Data of the complete structural analysis are summarized in Tabs. I and II. The final R-values are R = 6.09%, Rw= 4.19%, Rg = 4.95%.

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