Majzlan, Juraj, Plumhoff, Alexandra, Števko, Martin, Steciuk, Gwladys, Plášil, Jakub, Dachs, Edgar, Benisek, Artur (2023) Thermodynamic and structural variations along the olivenite–libethenite solid solution. European Journal of Mineralogy, 35 (2). 157-169 doi:10.5194/ejm-35-157-2023
| Reference Type | Journal (article/letter/editorial) | ||
|---|---|---|---|
| Title | Thermodynamic and structural variations along the olivenite–libethenite solid solution | ||
| Journal | European Journal of Mineralogy | ||
| Authors | Majzlan, Juraj | Author | |
| Plumhoff, Alexandra | Author | ||
| Števko, Martin | Author | ||
| Steciuk, Gwladys | Author | ||
| Plášil, Jakub | Author | ||
| Dachs, Edgar | Author | ||
| Benisek, Artur | Author | ||
| Year | 2023 (March 21) | Volume | < 35 > |
| Page(s) | 157-169 | Issue | < 2 > |
| Publisher | Copernicus GmbH | ||
| URL | |||
| DOI | doi:10.5194/ejm-35-157-2023Search in ResearchGate | ||
| Generate Citation Formats | |||
| Original Entry | Majzlan, J., Plumhoff, A., Števko, M., Steciuk, G., Plášil, J., Dachs, E., and Benisek, A. (2023): Thermodynamic and structural variations along the olivenite–libethenite solid solution. European Journal of Mineralogy, 35, 157-169. https://ejm.copernicus.org/articles/35/157/2023/ | ||
| Classification | Not set | LoC | Not set |
| Mindat Ref. ID | 16115203 | Long-form Identifier | mindat:1:5:16115203:1 |
| GUID | 0 | ||
| Full Reference | Majzlan, Juraj, Plumhoff, Alexandra, Števko, Martin, Steciuk, Gwladys, Plášil, Jakub, Dachs, Edgar, Benisek, Artur (2023) Thermodynamic and structural variations along the olivenite–libethenite solid solution. European Journal of Mineralogy, 35 (2). 157-169 doi:10.5194/ejm-35-157-2023 | ||
| Plain Text | Majzlan, Juraj, Plumhoff, Alexandra, Števko, Martin, Steciuk, Gwladys, Plášil, Jakub, Dachs, Edgar, Benisek, Artur (2023) Thermodynamic and structural variations along the olivenite–libethenite solid solution. European Journal of Mineralogy, 35 (2). 157-169 doi:10.5194/ejm-35-157-2023 | ||
| In | Link this record to the correct parent record (if possible) | ||
| Abstract/Notes | Abstract. Many natural secondary arsenates contain a small fraction of phosphate. In this work, we investigated the olivenite–libethenite (Cu2(AsO4)(OH)–Cu2(PO4)(OH)) solid solution as a model system for the P–As substitution in secondary minerals. The synthetic samples spanned the entire range from pure olivenite (Xlib=0) to libethenite (Xlib=1). Acid-solution calorimetry determined that the excess enthalpies are non-ideal, with a maximum at Xlib=0.6 of +1.6 kJ mol−1. This asymmetry can be described by the Redlich–Kister equation of Hex= Xoli⋅Xlib [A+B(Xoli−Xlib)], with A=6.27 ± 0.16 and B=2.9 ± 0.5 kJ mol−1. Three-dimensional electron diffraction analysis on the intermediate member with Xlib=0.5 showed that there is no P–As ordering, meaning that the configurational entropy (Sconf) can be calculated as -R(XolilnXoli+XliblnXlib). The excess vibrational entropies (Svibex), determined by relaxation calorimetry, are small and negative. The entropies of mixing (Sconf+Svibex) also show asymmetry, with a maximum near Xlib=0.6. Autocorrelation analysis of infrared spectra suggests local heterogeneity that arises from strain relaxation around cations with different sizes (As5+ / P5+) in the intermediate members and explains the positive enthalpies of mixing. The length scale of this strain is around 5 Å, limited to the vicinity of the tetrahedra in the structure. At longer length scales (≈15 Å), the strain is partially compensated by the monoclinic–orthorhombic transformation. The volume of mixing shows complex behavior, determined by P–As substitution and symmetry change. A small (0.9 kJ mol−1) drop in enthalpies of mixing in the region of Xlib=0.7–0.8 confirms the change from monoclinic to orthorhombic symmetry. | ||
Mineral Pages
| Mineral | Citation Details |
|---|---|
| Libethenite | |
| Libethenite-Olivenite Series | |
| Olivenite |
See Also
These are possibly similar items as determined by title/reference text matching only.
