Evidence of non‐linear to linear transformation of the normal state resistivity in YBCO at constant oxygen content
Bibliographic record
Abstract
Abstract We studied the origin of variation in the magnitude and temperature dependence of the normal state resistivity frequently observed in different Y Ba2Cu3O7–δ (YBCO) single crystal or thin film samples with the same T C. We investigated the temperature dependence of resistivity in YBCO thin films, which were subjected to annealing in argon at 120 – 140 °C or aging at room temperature in air. Before annealing (or aging) these films exhibited a non‐linear in‐plane resistivity ρ a b (T), with upward deviation (flattening) in ρ a b (T) from the linear high temperature behavior below 220‐230 K. For all films the annealing causes an increase of resistivity and a transformation of ρ a b (T) from a non‐linear dependence towards a more linear one (less flattening). Our proposed model provides explanation of these phenomena based on the thermally activated redistribution of residual O(5) oxygen in the chain‐layer of YBCO without any change in the overall oxygen content within the sample. The results show that a perfectly linear ρ (T) can be observed in YBCO of oxygen content 7 – δ as low as 6.8. The agreement between the our data for ρ a b (T; t) and the proposed model was very good. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
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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".