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Record W1990495674 · doi:10.1063/1.2202291

Synthesis and characterization of polyureasilazane derived SiCN ceramics

2006· article· en· W1990495674 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueJournal of Applied Physics · 2006
Typearticle
Languageen
FieldMaterials Science
TopicAdvanced ceramic materials synthesis
Canadian institutionsConcordia University
Fundersnot available
KeywordsElectron paramagnetic resonanceDangling bondLaser linewidthMaterials scienceAtmospheric temperature rangeAnalytical Chemistry (journal)PyrolysisCeramicBand gapParamagnetismNuclear magnetic resonanceChemistryCondensed matter physicsSiliconComposite materialOrganic chemistryOptoelectronics

Abstract

fetched live from OpenAlex

Samples of SiCN ceramics were synthesized by thermal treatment of commercially available CERASET™ polyureasilazane, used as liquid-polymer precursor, at pyrolysis temperatures of 1000, 1050, 1100, 1150, and 1200°C. Electron paramagnetic resonance (EPR) signals due to sp2-hybridized carbon-related dangling bonds were recorded over the 4–300K temperature range at X band (9.6GHz), and the spectra showed the presence of an intense EPR line with g=2.0027 at room temperature for all samples; at liquid helium temperature an additional line was seen present as a shoulder to main line. These two signals are due to carbon-related dangling bonds present as (i) defects on the free-carbon phase and (ii) within the bulk of SiCN ceramic network. The value of the antiferromagnetic exchange constant between dangling bonds in the various samples, not hitherto available in the literature, was estimated from the temperature variation of the EPR linewidth to be anywhere from J=−12 to J=−15K in the samples synthesized at 1000, 1100, and 1150°C. The EPR linewidth of the samples decreased with increasing pyrolysis temperature of a sample, being 0.07mT at X band at room temperature for the samples synthesized at 1150 and 1200°C, which can be used potentially as stable g markers, due to their very narrow linewidth. The W-band (95GHz) room-temperature spectrum of the sample pyrolyzed at 1100°C exhibited only one line consistent with the X-band spectrum. At higher frequency of G band (170GHz) the EPR spectra are better resolved, clearly showing the presence of a strong (g=2.0027) and a weak (g=2.0032) EPR line at room temperature, and the latter corresponds to the line present at X band as shoulder at liquid-helium temperature. In addition, nuclear magnetic resonance measurements were carried out to confirm the existence of free-carbon phase and oxygen atoms in the samples.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.003
Threshold uncertainty score0.555

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.007
GPT teacher head0.206
Teacher spread0.199 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it