Ferromagnetism in Annealed Ce<SUB>0.95</SUB>Co<SUB>0.05</SUB>O<SUB>2</SUB> and Ce<SUB>0.95</SUB>Ni<SUB>0.05</SUB>O<SUB>2</SUB> Nanoparticles
Bibliographic record
Abstract
This paper reports an investigation on the role of transition-metal ions in producing ferromagnetism in CeO2 nanoparticles by electron paramagnetic resonance (EPR). Several samples of CeO2 nanoparticles annealed at 200, 300, 400, and 500 degrees C, doped with 5% Ni and 5% Co ions, characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetry analysis (TGA) and mass spectroscopy (MS), were investigated by X-band EPR at 4, 10 and 300 K, and by magnetometry at 300 K. Magnetic properties and EPR/FMR (Ferromagnetic Resonance) spectra of these nanoparticle samples were found to depend strongly on the annealing temperature (T(A)), oxygen stoichiometry, and dopant-ion species. Different behavior of saturation magnetization in the samples with the dopants, Co and Ni, is found to be due to different-inward and outward-surface diffusion of these impurity ions, respectively, during annealing. A detailed simulation of EPR/FMR spectra of isolated Co and Ni ions carried out here provides in-depth details on the role of the doped ions and oxygen (O-) defects played in the observed magnetic properties.
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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 | 0.025 | 0.013 |
| Meta-epidemiology (narrow) | 0.013 | 0.013 |
| Meta-epidemiology (broad) | 0.017 | 0.004 |
| Bibliometrics | 0.012 | 0.021 |
| Science and technology studies | 0.010 | 0.022 |
| Scholarly communication | 0.009 | 0.018 |
| Open science | 0.025 | 0.013 |
| Research integrity | 0.011 | 0.009 |
| Insufficient payload (model declined to judge) | 0.002 | 0.005 |
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; both teacher heads agree on what is shown here.
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".