Infrared transmission study of crystal-field excitations in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">La</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mi>−</mml:mi><mml:mi>x</mml:mi><mml:mi>−</mml:mi><mml:mi>y</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Nd</mml:mi></mml:mrow><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Sr</mml:mi></mml:mrow><mml:mrow><mml:mi>y</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">CuO</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>
Bibliographic record
Abstract
We report an infrared crystal field study of ${\mathrm{La}}_{2\ensuremath{-}x\ensuremath{-}y}{\mathrm{Nd}}_{x}{\mathrm{Sr}}_{y}{\mathrm{CuO}}_{4}$ single crystals for $(x=0.35,$ $y=0),$ $(x=0.34,y=0.14),$ and $(x=0.42,y=0.19).$ ${\mathrm{Nd}}^{3+}$ crystal field excitations from the ground state multiplet ${}^{4}{I}_{9/2}$ to the ${}^{4}{I}_{11/2},$ ${}^{4}{I}_{13/2},$ ${}^{4}{I}_{15/2},$ and ${}^{4}{F}_{3/2}$ excited multiplets are observed. A precise set of crystal field parameters, that reproduces the ${\mathrm{Nd}}^{3+}$ electronic levels in all the samples as well as the ${\mathrm{La}}_{1.65}{\mathrm{Nd}}_{0.35}{\mathrm{CuO}}_{4}$ susceptibility measurements as a function of temperature, is determined. A very strong Ising-like anisotropy of the low-temperature ${\mathrm{Nd}}^{3+}$ magnetic moment is related to a large value of the second rank crystal field parameter ${B}_{20}.$ In addition to the ${\mathrm{Nd}}^{3+}$ ${C}_{4v}$ symmetry regular site a second one, of lower symmetry, is detected and related to possible stripe formation.
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How this classification was reachedexpand
Direct model labels (unvalidated)
Per-model category and study-design labels from the labeling rounds. They are machine output, unvalidated, and the disagreement between models ships as data. No study design here is MEDLINE-validated yet.
| Model arm | Categories | Study design | Confidence |
|---|---|---|---|
| gemma | no category Domain: not available · Genre: Empirical About the Canadian research system: no · About a Canadian topic: no | Bench or experimental | low |
| gpt | Insufficient payload (model declined to judge) Domain: not available · Genre: Other About the Canadian research system: no · About a Canadian topic: no | Not applicable | low |
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.010 | 0.008 |
| Meta-epidemiology (narrow) | 0.005 | 0.012 |
| Meta-epidemiology (broad) | 0.002 | 0.011 |
| Bibliometrics | 0.004 | 0.008 |
| Science and technology studies | 0.008 | 0.010 |
| Scholarly communication | 0.009 | 0.011 |
| Open science | 0.013 | 0.011 |
| Research integrity | 0.012 | 0.011 |
| Insufficient payload (model declined to judge) | 0.992 | 0.012 |
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, unvalidatedLabeled directly by 2 models reading the full record.
The models disagree on parts of this classification; every voice is preserved in the section at the end of the page.
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".