Micromagnetics of paleomagnetically significant mineral grains with complex morphology
Bibliographic record
Abstract
Micromagnetic calculations relevant to paleomagnetism have generally focused on ideal shapes such as spheres and cubes. However, oxide grains that occur naturally in rocks often have irregular morphologies, highly skeletal dendritic forms being particularly common. To investigate the potential effects of complex grain morphology on magnetic stability, we have carried out two parallel sets of calculations. The first is based on randomly distorted 30–120 nm magnetite spheres. We use a three‐dimensional finite element/boundary integral micromagnetic model able to generate suitable morphologies unrestricted by the regular cell structure required by finite difference models. The second model consists of a 300 nm magnetite octahedron from which most of the material has been removed to leave a small octahedral crystallite at each of the six apices connected by an orthogonal framework of thin rods. The results obtained imply that micromagnetic models currently provide no unambiguous evidence that morphological complexities endow magnetite nanoparticles with enhanced coercivity.
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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 | 0.001 |
| 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".