SITE OCCUPANCY OF Co AND Ni IN ERYTHRITE ANNABERGITE SOLID SOLUTIONS DEDUCED BY VIBRATIONAL SPECTROSCOPY
Bibliographic record
Abstract
Members of the solid-solutions series between erythrite [Co3(AsO4)2.8H2O] and annabergite [Ni3(AsO4)2.8H2O] were synthesized and studied by a combination of X-ray diffraction, scanning electron microscopy, and Raman and infrared spectroscopy. The solid solution is complete, with the monoclinic C2/m space group being retained throughout. The unit-cell parameters decrease in size along all crystallographic directions as the amount of Ni increases. The β angle in the unit cell also decreases from 105.05(1) ° (erythrite) to 104.90(1) ° (annabergite). Crystals of annabergite and samples with high Ni content elongate along the a axis, contrasting with crystals of erythrite and Co-rich samples, which elongate along c. In the Raman and infrared spectra of the synthetic minerals, the band positions shift in accordance with the increase in bond strength associated with the decrease in the unit-cell parameters. Trends in Raman band positions of the antisymmetric arsenate stretching vibrations are sensitive to the site occupancy of metal ions in the crystal structure. Changes in the crystal morphology, unit-cell parameters and vibrational spectra have been rationalized in terms of the site occupancy of Co and Ni in the crystal structure. Substitution of Ni is directed to metal site 1 (C2h site symmetry) whereas Co is directed to metal site 2 (C2 site symmetry). Raman spectroscopy has proved to be useful for the determination of site occupancy of metal ions in solid solutions of minerals.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".