Redetermination of the<i>γ</i>-form of tellurium dioxide

Weil, Mat­thias

doi:10.1107/s2414314617017576

Cited by 6 publications

(3 citation statements)

References 13 publications

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“…Upper panel: X-ray radial distribution functions (RDFs) with the Q -dependent Te–O pair weighting divided out, prior to sine Fourier transform of the interference functions of Figure , using Q max = 21.39 Å –1 . Also shown is the Te–O RDF in γ-TeO 2 , calculated using the XTAL program and convolved with the same instrumental broadening as the X-ray data and a thermal broadening of 0.07 Å. Middle panel: running Te–O coordination numbers ( n TeO ( r )), obtained by integration of the RDFs with the lower limit of the integral set to the zero-crossing at ∼1.72(1) Å.…”

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confidence: 99%

Short-Range Disorder in TeO₂ Melt and Glass

Alderman

Benmore

Feller

et al. 2019

J. Phys. Chem. Lett.

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High-resolution X-ray pair distribution functions for molten and glassy TeO2 reveal coordination numbers n TeO ≈ 4. However, distinct from the known α-, β-, and γ-TeO2 polymorphs, there is considerable short-range disorder such that no clear cutoff distance between bonded and nonbonded interactions exists. We suggest that this is similar to disorder in δ-TeO2 and arises from a broad distribution of asymmetric Te–O–Te bridges, something that we observe becomes increasingly asymmetric with increasing liquid temperature. Such behavior is qualitatively consistent with existing interpretations of Raman scattering spectra, and equivalent to temperature-induced coordination number reduction, for sufficiently large cutoff radii. Therefore, TeO2 contains a distribution of local environments that are, furthermore, temperature dependent, making it distinct from the canonical single-oxide glass formers. Our results are in good agreement with high-level ab initio cluster calculations.

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confidence: 99%

Short-Range Disorder in TeO₂ Melt and Glass

Alderman

Benmore

Feller

et al. 2019

J. Phys. Chem. Lett.

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“…In the figure, two black arrows indicate where the two strongest reflections from γ-TeO 2 would be expected, matching well with the strongest extrinsic reflections. 20 A similar refinement of the pXRD data is shown in Figure S2 .…”

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confidence: 58%

“…The area shown in gray was not included in the refinement. The two black arrows indicate where the strongest reflections from γ-TeO 2 would be expected 20.…”

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confidence: 99%

X-ray and Neutron Diffraction Studies of SrTe₂FeO₆Cl, an Oxide Chloride with Rare Anion Ordering

et al. 2023

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The oxychloride SrTe 2 FeO 6 Cl is obtained by hightemperature solid-state synthesis under inert conditions in closed reaction vessels. The compound crystallizes in a novel monoclinic crystal structure that is described in the space group P12 1 /n1 (No. 14). The unit cell parameters, a = 10.2604(1) Å, b = 5.34556(5) Å, c = 26.6851(3) Å, and β = 93.6853(4)°, and atomic parameters were determined from synchrotron diffraction data, starting from a model that was obtained from single-crystal X-ray diffraction data. The anion lattice exhibits a rare ordering of oxide and chloride ions: onedimensional zig-zag ladders of chlorine (squarelike motif) are surrounded by an oxygen matrix. Two different iron sites coordinated solely to oxygen are present in the structure, one octahedral and one square pyramidal, both distorted. Similarly, two different strontium coordinations are present; the first homoleptic coordinated to eight oxygen atoms and the second heteroleptic coordinated to four oxygen and four chlorine atoms in a fac-like manner. The lone pair of Te(IV) is directed toward the larger chlorine atoms. Magnetic susceptibility measurements confirm that Fe is +3 (d 5 ) in the highspin electronic configuration, exhibiting an almost ideal spin-only moment, μ eff = 5.65 μ B Fe −1 . The slightly negative Weiss constant (θ CW = −39 K) suggests dominating antiparallel spin-to-spin coupling in the paramagnetic temperature range, agreeing with an observed long-range antiferromagnetic spin ordering below Neél temperature, T N ∼ 13 K, and a broad second order-like anomaly in the specific heat measurement data. Low-temperature neutron diffraction data reveal that the antiferromagnetic ordered phase is Ctype, with a k-vector (1/2, 1/2, 0) and ordered moment of 4.14(7) μ B . The spin structure can be described as antiferromagnetic ordered layers stacked along the a-axis, forming layers of squares that alternate along the c-axis.

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Phase formation studies and crystal structure refinements in the Mn^II/Te^IV/O/(H) system

Weil

Eder

2022

Zeitschrift anorg allge chemie

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Systematic phase formation studies in the system MnII/TeIV/O/‐(H) using either solid‐state reactions between stoichiometric MnO:TeO2 mixtures or hydrothermal reactions under basic conditions led to crystal growth of two polymorphs (α‐, γ‐) of MnTeO3, Mn6Te5O16, Mn15(TeO3)14(OH)2 and Mn3(TeO3)2(OH)2. Although α‐MnTeO3 and Mn6Te5O16 have been reported previously, crystal structure refinements were missing so far. Whereas α‐MnTeO3 crystallizes in a unique structure (space group Pbca, Z=16), Mn6Te5O16 (Pnma, Z=4) is isotypic with its Co‐homologue. The previously unknown phases γ‐MnTeO3 (Pbca, Z=8), Mn15(TeO3)14(OH)2 ( Rtrue3‾ ${R\bar{3}}$ , Z=3) and Mn3(TeO3)2(OH)2 (P63mc, Z=4) all have isotypic relationships, namely with ZnTeO3, Co15(TeO3)14F2 and M3(TeO3)2(OH)2 (M=Ni, Co), respectively. Common to all crystal structures of the five manganese(II) oxidotellurate(IV) phases is the presence of [MnO5] or [MnO6] polyhedra and isolated trigonal‐pyramidal [TeO3] groups (except for one of the TeIV atoms in Mn6Te5O16 [TeO4] bisphenoids) as principal building units, which share corners and edges with the [MnO5/6] groups. The resulting three‐dimensional frameworks are dominated by the influence of the stereochemically active 5 s2 electron lone pair situated at the TeIV atom, leading to the formation of channels or interstices. Quantitative comparisons between the corresponding isotypic crystal structures are given.

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Redetermination of theγ-form of tellurium dioxide

Cited by 6 publications

References 13 publications

Short-Range Disorder in TeO₂ Melt and Glass

Short-Range Disorder in TeO₂ Melt and Glass

X-ray and Neutron Diffraction Studies of SrTe₂FeO₆Cl, an Oxide Chloride with Rare Anion Ordering

Phase formation studies and crystal structure refinements in the Mn^II/Te^IV/O/(H) system

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Redetermination of theγ-form of tellurium dioxide

Cited by 6 publications

References 13 publications

Short-Range Disorder in TeO2 Melt and Glass

Short-Range Disorder in TeO2 Melt and Glass

X-ray and Neutron Diffraction Studies of SrTe2FeO6Cl, an Oxide Chloride with Rare Anion Ordering

Phase formation studies and crystal structure refinements in the MnII/TeIV/O/(H) system

Contact Info

Product

Resources

About

Short-Range Disorder in TeO₂ Melt and Glass

Short-Range Disorder in TeO₂ Melt and Glass

X-ray and Neutron Diffraction Studies of SrTe₂FeO₆Cl, an Oxide Chloride with Rare Anion Ordering

Phase formation studies and crystal structure refinements in the Mn^II/Te^IV/O/(H) system