β-detected NMR Study of Semi-Insulating GaAs
Bibliographic record
Abstract
A beta-detected NMR experiment is carried out on a semi-insulating GaAs crystal using a low energy spin polarized 8 Li + beam to investigate the magnetic properties as a function of temperature and depth. The range of depths probed, from ∼137 nm down to ∼17 nm, coincides with the region of electronic band-bending due to the surface. We find a resonance broadened by the host nuclear dipoles, consistent with an earlier report[6], but using a pulsed radio frequency scheme, we are able to make higher resolution measurements. We find a small negative shift of the resonance (relative to an MgO reference) at room temperature that is independent of depth. Remarkably, as the temperature is reduced below about 150 K, the resonance shifts negatively and becomes depth dependent, with a larger negative shift deeper into the sample. This shift saturates below 10 K, i.e. it does not follow a Curie's law that might be expected for dilute magnetic impurities. Possible origins are discussed.
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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".