Electron paramagnetic resonance studies of the E′ centers in alpha-quartz
Bibliographic record
Abstract
Room-temperature electron paramagnetic resonance (EPR) studies (at ca. 9.85 GHz) of γ- and x-irradiated alpha-quartz are reported and discussed. The previously described E′2 center has been proved to be associated with hydrogen, and this center’s primary silicon-29 hyperfine coupling matrix has now been accurately determined, as were its hydrogen hyperfine coupling and electronic Zeeman splitting (g) matrices. The paramagnetic center is believed to arise from attack on a diamagnetic oxygen-anion vacancy V(O0) (E center) effectively by an electron and a proton arising from atomic hydrogen produced in the irradiation process. A second very similar center, called E′2(II) herein, was discovered and its parameter matrices too have been obtained by EPR, and it was modelled as described herein. It is proposed that the proton in E′2 resides on an oxygen anion adjacent to the vacancy species. Comparison is made of the spin-Hamiltonian parameter matrices and the choice of best symmetry-related sites expressing them, for the various centers E′1–E′4. PACS Nos.: 76.30.–v,61.72.Hh, 76.30.Mi, 42.70.Ce, 61.80.–x, 61.72.–y
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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) | 0.002 | 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".