A single-crystal X-ray and Raman spectroscopic study of hydrothermally synthesized arsenates and vanadates with the descloizite and adelite structure types

Autor(en)
Tamara Đorđević, Uwe Kolitsch, Lutz Nasdala
Abstrakt

Studying the reason for the formation of two structural sub-types, seven arsenate and vanadate compounds of descloizite and adelite groups [specifically (1) CdCo(OH)(AsO

4), (2) CdCu(OH) (AsO

4), (3) SrCo(OH)(AsO

4), (4) SrZn(OH)(AsO

4), (5) SrCu(OH)(VO

4), (6) CdCo(OH)(VO

4), and (7) CdCu(OH)(VO

4) (bold numbers throughout paper refer to these compounds)] were synthesized under low-temperature hydrothermal conditions. 1-2 and 6-7 are isostructural with descloizite, and 3-5 are with adelite-group minerals and several synthetic compounds. Together with a sample of conichalcite, (8) CaCu(OH)(AsO

4), they were investigated using single-crystal X-ray diffraction [R(F) = 0.0153-0.0283 for 1-5 and 8; for 6 and 7, R(F) = 0.0603 and 0.0444, respectively] and Raman spectroscopy. Although crystallizing in different orthorhombic space groups, the atomic arrangements of descloizite-(Pnam) and adelite-(P2

12

12

1) type compounds adopt the same topology: the atomic arrangement is characterized by M2O

6 octahedrons (M2 = Mg

2+, Al

3+, Mn

2+,3+, Fe

2+, Co

2+, Ni

2+, Cu

2+, Zn

2+) edge-linked into chains. These chains are interconnected by XO

4 tetrahedrons (X = Si

4+, P

5+, V

5+, As

5+, Mo

6+) into a three-dimensional framework. Cavities host M1 atoms (M1 = Na

+, Ca

2+, Cd

2+, Hg

2+, Pb

2+); their coordination varies from 7 for descloizite-type representatives to 8 for adelite-type structures. The OH stretching frequencies in the Raman spectra are in good agreement with the observed O-H...O donor-acceptor distances. A detailed discussion of the crystal chemistry of these compounds and their influence on the space-group symmetry indicate a distinct dependence of the structural changes on the average ionic radii (r

M1 + r

X)/2.

Organisation(en)
Institut für Mineralogie und Kristallographie
Externe Organisation(en)
Naturhistorisches Museum Wien (NHM)
Journal
American Mineralogist: an international journal of earth and planetary materials
Band
101
Seiten
1135-1149
Anzahl der Seiten
15
ISSN
0003-004X
DOI
https://doi.org/10.2138/am-2016-5422
Publikationsdatum
05-2016
Peer-reviewed
Ja
ÖFOS 2012
104026 Spektroskopie, 105116 Mineralogie, 105113 Kristallographie
Schlagwörter
ASJC Scopus Sachgebiete
Geochemistry and Petrology, Geophysics
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/a-singlecrystal-xray-and-raman-spectroscopic-study-of-hydrothermally-synthesized-arsenates-and-vanadates-with-the-descloizite-and-adelite-structure-types(789fe90c-1b67-4160-885b-57b4e5ad29ec).html