EXSOLUTION AND BREAKDOWN OF SCANDIAN AND TUNGSTENIAN Nb Ta Ti Fe Mn PHASES IN NIOBIAN RUTILE
Bibliographic record
Abstract
Niobian rutile commonly exsolves titanian ferrocolumbite to manganocolumbite or ixiolite with elevated contents of Nb, Mn and Sc, W or Sn, but further breakdown of the exsolved phase has not been reported to date. Niobian rutile from Eptevann, southern Norway, exsolved titanian-scandian phase E1 of the A3+BO4 type, which subsequently broke down to a (Sc,Mn)-en-riched and U-depleted phase E2 (11 to 12.8 wt. % Sc2O3), a Ti-rich but (Sc,Mn,U)-poor phase E3, and a (U,Y)-rich but (Ti,Sc,Mn)-depleted, metamict and hydrous phase X (2.5 to 3 wt. % UO2). Niobian rutile from Ilmen Mountains, Russia, exsolved a (Ti,U)-poor, Mn-rich tungstenian ixiolite (10 to 14 wt. % WO3), which subsequently broke down into a Ti-poor but W-rich phase (~30 wt. % WO3) and a U-enriched but W-depleted mineral (~6 wt. % WO3, 0.7 to 1.5 wt. % UO2). The second-stage breakdown of the exsolved phases reflects the metastable nature of these minerals, which feature disordered populations of divalent to hexavalent cations in an exclusively octahedral array of oxygen anions, with consequent long-range disorder and local imbalances of electro-static charges. Under low-temperature conditions, insufficient for further exsolution and ordering, the exsolved phases readily respond to the action of aqueous fluids by breakdown to more cation-selective phases. However, incomplete separation of differ-ent categories of cations and non-integral stoichiometries of the products suggest that they did not attain equilibrium.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".