Oxydes de plomb. I. Structure cristalline du minium Pb3O4, à température ambiante (293 K)

Gavarri, J.R.; Weigel, D.

doi:10.1016/0022-4596(75)90127-9

Cited by 51 publications

(20 citation statements)

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“…22). There is a marked resemblance to the tetragonal structure of minium, Pb 4+ Pb 2 2+ O 4 (Gavarri and Weigel, 1975) (Marezio and Remeika, 1967 (Glazer, 1972), producing a unit cell with space group Pnma and cell parameters √2 × 2 × √2 of the aristotypical perovskite cube. Bending of Fe-O-Fe links and displacement of Gd in GdFeO 3 reduce the Gd coordination from 12 equidistant oxygen atoms to six at 2.26-2.39 Å, two at 2.82 Å and four effectively non-bonded oxygen atoms at >3.1 Å (Coppens and Eibschuetz, 1965 : a square pyramid with four V-O distances 1.78-2.00 Å, and a very short distance of 1.58 Å corresponding to an apical V=O double bond.…”

Section: +mentioning

confidence: 99%

“…44). Gavarri and Weigel, 1975) and has rutile-like edgesharing chains of octahedra containing Fe ) bridges, with oxidation of some octahedral Fe 2+ to Fe 3+ in order to maintain electroneutrality (Mellini and Merlino, 1981 )O 12 (Cl 2 ). It thus represents an intermediate member of a series between two hypothetical end-members, with the interesting complication that it is not possible to write a formula that both makes crystal-chemical sense and is electrostatically neutral.…”

Section: +mentioning

confidence: 99%

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A review of the structural architecture of tellurium oxycompounds

2016

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Relative to its extremely low abundance in the Earth's crust, tellurium is the most mineralogically diverse chemical element, with over 160 mineral species known that contain essential Te, many of them with unique crystal structures. We review the crystal structures of 703 tellurium oxysalts for which good refinements exist, including 55 that are known to occur as minerals. The dataset is restricted to compounds where oxygen is the only ligand that is strongly bound to Te, but most of the Periodic 4+ cations display one-sided 3-, 4-or 5-coordination by oxygen (with rare examples of coordination numbers 2 and 6). For both valence states of Te, examples are known of Te m O n complexes which are monomeric (m = 1; neso), noncyclic finite oligomers (soro), rings (cyclo), infinite chains (ino), layers ( phyllo) and frameworks (tecto tellurates). There is a clear analogy to the polymerization classes that are known for silicate anions, but the behaviour of Te is much richer than that of Si for several reasons: (1) the existence of two cationic valence states for Te; (2) the occurrence of multiple coordination numbers; (3) the possibility of edge-sharing by TeO n polyhedra; (4) the possibility for oxygen ligands to be 3-coordinated by Te; and (5) the occurrence of Te m O n polymers that are cationic, as well as neutral or anionic. While most compounds contain only one or two symmetrically distinct types of Te atom, Pauling's Fifth Rule is frequently violated, and stoichiometrically simple compounds such as CaTeO 3 can have polymorphs with up to 18 distinct Te sites. There is a tendency for local symmetry features such as the threefold axis of a TeO 6 octahedron or the acentric symmetry of a Te 4+ O n polyhedron to be inherited by the host structure; the latter in particular can lead to useful physical properties such as nonlinear optical behaviour. We develop for the first time a hierarchical taxonomy of Te-oxysalt structures, based upon (1) valence state of Te; (2) polymerization state of Te m O n complexes; (3) polymerization state of larger strongly-bound structural units that include non-Te cations. Structures are readily located and compared within this classification.

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Section: +mentioning

confidence: 99%

Section: +mentioning

confidence: 99%

A review of the structural architecture of tellurium oxycompounds

2016

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“…From a total of 31 individual lattice fringe measurements, five sets of d-spacings were identified ( Table 1). The length of the different vectors defining the d-spacings were compared with the calculated d-spacings of pure lead (20), Pb-oxides (21)(22)(23)(24), and trigonal (24) and hexagonal (25) Pb-silicate (Table 1). The number and length of measured d-spacings match the cubic structure of native Pb.…”

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Metallic lead nanospheres discovered in ancient zircons

Kusiak

Dunkley

Wirth

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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Zircon (ZrSiO 4 ) is the most commonly used geochronometer, preserving age and geochemical information through a wide range of geological processes. However, zircon U-Pb geochronology can be affected by redistribution of radiogenic Pb, which is incompatible in the crystal structure. This phenomenon is particularly common in zircon that has experienced ultra-high temperature metamorphism, where ion imaging has revealed submicrometer domains that are sufficiently heterogeneously distributed to severely perturb ages, in some cases yielding apparent Hadean (>4 Ga) ages from younger zircons. Documenting the composition and mineralogy of these Pb-enriched domains is essential for understanding the processes of Pb redistribution in zircon and its effects on geochronology. Using high-resolution scanning transmission electron microscopy, we show that Pb-rich domains previously identified in zircons from East Antarctic granulites are 5-30 nm nanospheres of metallic Pb. They are randomly distributed with respect to zircon crystallinity, and their association with a Ti-and Al-rich silica melt suggests that they represent melt inclusions generated during ultra-high temperature metamorphism. Metallic Pb is exceedingly rare in nature and previously has not been reported in association with high-grade metamorphism. Formation of these metallic nanospheres within annealed zircon effectively halts the loss of radiogenic Pb from zircon. Both the redistribution and phase separation of radiogenic Pb in this manner can compromise the precision and accuracy of U-Pb ages obtained by high spatial resolution methods.metallic Pb | nanospheres | zircon | Antarctica | early Earth Z ircon is the mineral of choice for precisely determining the timing of both magmatism and metamorphism in a wide range of geological samples as well as providing constraints on the source and time of deposition of clastic sedimentary rocks. Accurate zircon geochronometry is facilitated by zircon having a lattice structure that is stable over a wide range of temperatures and pressures (1), together with the fact that whatever Pb is present derives almost entirely from radioactive decay of U and Th. During its growth, zircon incorporates small amounts of nonformula elements, including Hf, Ti, and Y, and rare earth elements, U and Th, but generally excludes Pb. This incompatibility of Pb raises questions about how radiogenic Pb is retained in zircon, especially through geological events where elevated temperature, fluid activity, and deformation can enhance element mobility. Furthermore it has been established that an irregular redistribution of lead in metamorphic zircon can degrade the precision and accuracy of U-Pb isotopic data, in extreme cases leading to spurious ages (2, 3).Experimental and natural studies have revealed that element mobility in zircon is strongly dependent on the accumulation of α-recoil damage (4, 5). Multiple α-decay events along the U and Th decay chains leading to stable daughter Pb isotopes destroy the crystal lattice, creating amorphous ...

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“…Pb 3 O 4 , or, mineralogically, minium, which can also be represented by the formula 2PbOÁPbO 2 that indicates its lead(II,IV) nature, manifests itself as red tetrahedral crystals consisting of Pb IV O 6 octahedra joined at their edges [26]. The interatomic Pb IV -O and Pb II -O are interesting in that the oxygen octahedra around Pb IV atoms reveal bonds that are atypically long, and the Pb II atoms are atypically short.…”

Section: Synthesis Of Pb 3 Omentioning

confidence: 99%

Lead Oxides: Synthesis and Applications

Perry

2010

Transparent Electronics

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Oxydes de plomb. I. Structure cristalline du minium Pb3O4, à température ambiante (293 K)

Cited by 51 publications

References 9 publications

A review of the structural architecture of tellurium oxycompounds

A review of the structural architecture of tellurium oxycompounds

Metallic lead nanospheres discovered in ancient zircons

Lead Oxides: Synthesis and Applications

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