Study of Metal Extracted from Tzarev L5 Chondrite by Mössbauer Spectroscopy and Metalography
Bibliographic record
Abstract
Introduction: Mossbauer spectra of ordinary chondrites consist of several components related to metal, troilite, olivine, pyroxene, and iron oxides. The area of metal subspectra does not exceed 20% and this value is related to the metal iron content. Usually chondrite metal contains more than one metal phase, but they cannot be resolved in complicated Mossbauer spectrum of chondrite sample [1, 2]. Therefore, metal extraction from meteorite matter is necessary for detailed study by Mossbauer spectroscopy. Methods: A sample of metal extracted from ordinary chondrite Tzarev L5 was prepared as powder and glued on pure aluminum foil. Extraction was performed by several steps: powdering, levigation in acetone followed by the separation in strong and weak magnetic fields, then drying and etching by weak HF, and final selection with binocular loupe from silicates. Mossbauer spectrum was measured at room temperature using spectrometer SM-2201 with high accuracy, stability, and sensitivity in transmission geometry with moving absorber. Sections of Tzarev L5 for metallography were polished with diamond paste and etched by Nital (2 vol% HNO3, balance ethyl alcohol). Chemical composition of metal was obtained by microanalysis EDAX realized on SEM. Results: Mossbauer spectrum of metal from Tsarev L5 was measured with high velocity resolution using 4096 channels and than presented in 1024 channels for fitting. The results of the spectrum better fit demonstrated the presence of three sextets with the hyperfine field values related to kamacite α-Fe(Ni,Co), martensite α2-Fe(Ni,Co) and kamacite α′-Fe(Ni,Co), one doublet related to residue olivine, and one singlet related to taenite γFe(Ni,Co). The result of the metal grains metallography demonstrates the presence of various metal phases: α-Fe(Ni,Co), α2-Fe(Ni,Co), and both α′Fe(Ni,Co) and γ-Fe(Ni,Co) in plessite. Conclusions: Study of extracted metal from Tzarev L5 by Mossbauer spectroscopy permitted us to reveal four different metal phases and determine its hyperfine parameters and relative areas. These results were in good agreement with metallography data. References: [1] E. V. Zhiganova et al. 2005. Meteoritics & Planetary Science 40:A174. [2] E. V. Zhiganova et al. Hyperfine Interactions. Forthcoming. 5144 Si AND C ISOTOPIC RATIOS IN AGB STARS: SiC GRAIN DATA, MODELS, AND THE GALACTIC EVOLUTION OF THE Si ISOTOPES E. Zinner1, L. R. Nittler2, R. Gallino3, 7, A. I. Karakas4, M. Lugaro5, O. Straniero6, and J. C. Lattanzio7. 1Washington University, Saint Louis, Missouri 63130, USA. E-mail: ekz@wustl.edu. 2Carnegie Institution of Washington, NW Washington, D.C. 20015, USA. 3Universita di Torino, Italy. 4McMaster University, Hamilton, Ontario, L8S 4M1, Canada. 5University of Utrecht, 3508 TA Utrecht, The Netherlands. 6INAF, Osservatorio Astronomico di Teramo, Italy. 7Monash University, Victoria 3800, Australia
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How this classification was reachedexpand
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 | 0.000 | 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 teacher head, 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".