Linarite from Cap Garonne

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christian Paulsen ◽  
Christopher Benndorf ◽  
Daniel Günther ◽  
Oliver Oeckler ◽  
Helena Osthues ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Lone Pair ◽  
Electron Localization ◽  
Secondary Mineral ◽  
Synchrotron Diffraction ◽  
Teller Distortion ◽  
Localization Function ◽  
Jahn Teller ◽  
Jahn Teller Distortion

Abstract Linarite, PbCuSO4(OH)2, crystallizes as secondary mineral in form of clusters of crystals in Mine du Pradet at Cap Garonne in France. A tiny single crystal was isolated and its structure was refined from synchrotron diffraction data (λ = 0.049592 nm): P121/m1, a = 467.75(2), b = 563.48(4), c = 967.64(5) pm, β = 102.647(5)°, wR = 0.0544, 819 F 2 values and 56 variables. The proton positions were also refined. The Cu2+ cations are located within Cu(OH)2 ribbons and exhibit pronounced Jahn-Teller distortion (d(Cu–O): 2 × 191.9, 2 × 197.3 and 2 × 252.8 pm). The Cu(OH)2 ribbons are condensed with the sulfate tetrahedra and the lead cations. The latter are coordinated to eight oxygen atoms in a slightly anisotropic manner. Calculations of the electron localization function (ELF) of PbO (litharge), PbSO4 (anglesite) and PbCuSO4(OH)2 (linarite) show pronounced lone-pair character for PbO but rather isotropic ELF values around the lead cations in PbSO4 and PbCuSO4(OH)2.

Jahn-Teller distortion ordering in single-crystal Nd1/2Sr1/2MnO3

2004 ◽  
Vol 1 (7) ◽  
pp. 1641-1644 ◽  
Author(s):  
Mohammad E. Ghazi ◽  
P. D. Hatton
Keyword(s):  
Single Crystal ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion

Modifying Jahn-Teller distortion by epitaxial stress in LaMnO3 films for tunning electron localization

2021 ◽  
Author(s):  
Xin Chen ◽  
Baohua Wang ◽  
Tongxin Ge ◽  
Haoming Wei ◽  
Bingqiang Cao
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Reciprocal Space ◽  
Electron Localization ◽  
Electrical Transport Properties ◽  
High Quality ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Distortion

Abstract The effect of epitaxial stress on Jahn-Teller distortion in epitaxial LaMnO3 (LMO) films has been investigated. Both 2θ-ω scans and reciprocal space maps indicate that LMO samples are subjected to compressive stress. Obvious Laue oscillations can be detected in 2θ-ω scans, indicating the high quality of samples. Reciprocal space maps of symmetry peak (001) and asymmetry peak (-103) imply different epitaxial stress for LMO films deposited on different substrates. Raman spectra measurements reveal that the degree of Jahn-Teller distortion can be well tuned via the epitaxial stress which may further influence on the electron localization in the films. This study might benefit to understanding the correlation between crystalline structure and electrical transport properties of LMO films and related LMO-based superlattices.

scholarly journals (Na,□)5[MnO2]13nanorods: a new tunnel structure for electrode materials determinedab initioand refined through a combination of electron and synchrotron diffraction data

2016 ◽  
Vol 72 (6) ◽  
pp. 893-903 ◽  
Author(s):  
Enrico Mugnaioli ◽  
Mauro Gemmi ◽  
Marco Merlini ◽  
Michele Gregorkiewitz
Keyword(s):  
Diffraction Data ◽  
Electrode Materials ◽  
Rietveld Method ◽  
Unit Cell ◽  
Teller Distortion ◽  
Synchrotron Powder Diffraction ◽  
Jahn Teller ◽  
Crystal Electron ◽  
Jahn Teller Distortion ◽  
True Structure

(Nax□1 − x)5[MnO2]13has been synthesized withx= 0.80 (4), corresponding to Na0.31[MnO2]. This well known material is usually cited as Na0.4[MnO2] and is believed to have a romanèchite-like framework. Here, its true structure is determined,ab initio, by single-crystal electron diffraction tomography (EDT) and refined both by EDT data applying dynamical scattering theory and by the Rietveld method based on synchrotron powder diffraction data (χ2= 0.690,Rwp= 0.051,Rp= 0.037,RF2= 0.035). The unit cell is monoclinicC2/m,a= 22.5199 (6),b= 2.83987 (6),c= 14.8815 (4) Å, β = 105.0925 (16)°,V= 918.90 (4) Å3,Z= 2. A hitherto unknown [MnO2] framework is found, which is mainly based on edge- and corner-sharing octahedra and comprises three types of tunnels: per unit cell, two are defined by S-shaped 10-rings, four by egg-shaped 8-rings, and two by slightly oval 6-rings of Mn polyhedra. Na occupies all tunnels. The so-determined structure excellently explains previous reports on the electrochemistry of (Na,□)5[MnO2]13. The trivalent Mn3+ions concentrate at two of the seven Mn sites where larger Mn—O distances and Jahn–Teller distortion are observed. One of the Mn3+sites is five-coordinated in a square pyramid which, on oxidation to Mn4+, may easily undergo topotactic transformation to an octahedron suggesting a possible pathway for the transition among different tunnel structures.

Enhancement of the guest orderliness in a low-symmetric perovskite-type metal–organic framework influenced by Jahn–Teller distortion

2018 ◽  
Vol 20 (34) ◽  
pp. 21809-21813 ◽  
Author(s):  
M. Viswanathan
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Metal Organic Framework ◽  
Teller Distortion ◽  
Unusual Effect ◽  
Jahn Teller ◽  
Metal Organic ◽  
Jahn Teller Distortion ◽  
Perovskite Type ◽  
Organic Framework

Single-crystal neutron diffraction reveals an enhancement of the guest-orderliness in a low-symmetric MOF, with an opposite scenario for its high-symmetric cousin. The mechanism behind this unusual effect is proposed.

Effects of Temperature and Magnetic Fields on the Luminescence of Single Crystal (NH4)2TeCl6

1988 ◽  
Vol 43 (6) ◽  
pp. 555-560 ◽  
Author(s):  
K. Meidenbauer ◽  
G. Gliemann
Keyword(s):  
Excited State ◽  
Magnetic Fields ◽  
Single Crystal ◽  
Slow Component ◽  
Excited Electronic State ◽  
Luminescence Spectra ◽  
Teller Distortion ◽  
Field Dependent ◽  
Jahn Teller ◽  
Jahn Teller Distortion

The optical absorption of (NH4)2TeCl6 in acetonitrile at room temperature and the luminescence (spectra, decay curves) of single crystal (NH4)2TeCl6 at 1.9 K ≤ T ≤ 180K and at applied magnetic fields H (0 ≤ H ≤ 6 T) are reported. The temperature dependence of the luminescence indicates the existence of a metastable excited state energetically by ~ 80 cm−1 below a second excited state. With H || <111> the decay curves are monoexponential with magnetic field dependent slopes. H ||<001> yields biexponential decay curves, each composed of a slow component corresponding to the decay at H = 0, and of a field dependent fast component. The experimental results can be explained by effects of a tetragonal Jahn-Teller distortion due to a strong coupling of the excited electronic state 3Tlu of the Te(IV) ions and Eg vibration modes.

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