Structure of lead-free Tl-(Sb,As) chabournéite endmember

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Marco E. Ciriotti
Messaggi: 31675
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
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Structure of lead-free Tl-(Sb,As) chabournéite endmember

Messaggio da Marco E. Ciriotti » mar 03 ago, 2021 11:34

Prossima pubblicazione.

Referenza:
▪ Makovicky, E., Plášil, J., Kasatkin, A.V., Škoda, R. (2021): The Crystal Structure of Tl2.36Sb5.98As4.59S17, the Lead-Free Endmember of the Chabournéite Homeotypic Group. Canadian Mineralogist, 59, (in press).

Abstract:
The crystal structure of Tl2.36Sb5.98As4.59S17, the lead-free endmember of the chabournéite homeotypic group, from the Tl-As-Sb-rich gold deposit at Vorontsovskoye (the Urals, Russia) was determined and refined to R(obs) 0.099 for 9340 unique observed X-ray reflections. The triclinic unit-cell parameters determined from single-crystal data are as follows: a = 8.63253(19) Å, b = 16.3055(7) Å, c = 21.8196(8) Å, α = 75.094 (3)°, β = 83.631(2)°, γ = 89.303 (2)°, V = 2949.18(18) Å3 (Z = 4), P-1 space group. The crystal structure is composed of (001) slabs based on PbS and SnS archetypes, arranged in regular alternation. All Sb(As) distributions were studied in detail. The zig-zag boundary between the slabs is composed of a repeating sequence of [100] Tl-Tl, Sb-Sb (1/3 substituted by As), Tl-Tl, and Tl-Sb columns. Thallium forms tricapped trigonal coordination prisms and (Sb,As) forms bicapped prisms. Differences compared to two related structures—parapierrotite and tsygankoite—are specified. Twinning of chabournéite is connected with the (imperfect) order-disorder character of the structure, which is connected with the configurations observed on slab boundaries. The structure refinement of the lead-free Tl-(Sb,As) chabournéite endmember presented in this paper is the best starting point for a restudy of all complexities of the chabournéite homeotypic group.

NdR: il nome esatto del deposito è Vorontsovskoe (l'errore è soltanto nell'abstract).
Marco E. Ciriotti

«Things are interesting only in so far as they relate themselves to other things»

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Marco E. Ciriotti
Messaggi: 31675
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
Contatta:

Re: Structure of lead-free Tl-(Sb,As) chabournéite endmember

Messaggio da Marco E. Ciriotti » sab 28 ago, 2021 9:34

Pubblicazione effettuata.

Referenza:
▪ Makovicky, E., Plášil, J., Kasatkin, A.V., Škoda, R. (2021): The Crystal Structure of Tl2.36Sb5.98As4.59S17, the Lead-Free Endmember of the Chabournéite Homeotypic Group. Canadian Mineralogist, 59, 533-549.
Marco E. Ciriotti

«Things are interesting only in so far as they relate themselves to other things»

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