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Record W2082910903 · doi:10.1021/jp0218692

Effect of Yb<sup>3+</sup> Codoping on the Upconversion Emission in Nanocrystalline Y<sub>2</sub>O<sub>3</sub>:Er<sup>3+</sup>

2003· article· en· W2082910903 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

VenueThe Journal of Physical Chemistry B · 2003
Typearticle
Languageen
FieldMaterials Science
TopicLuminescence Properties of Advanced Materials
Canadian institutionsConcordia University
Fundersnot available
KeywordsNanocrystalline materialMaterials sciencePhoton upconversionAnalytical Chemistry (journal)ExcitationIonNanocrystalLuminescenceAtomic physicsChemistryNanotechnologyOptoelectronicsPhysics

Abstract

fetched live from OpenAlex

The Stokes emission of nanocrystalline and bulk Y 2 O 3:Er 3+, Yb 3+ following 488 nm were reported. Two nanocrystalline samples were studied, one produced via propellant synthesis and the other via wet synthesis. Green, red, and NIR emission from the Er 3+ ion was observed in both bulk and nanocrystalline samples. Emission from the 2 F 5/2 → 2 F 7/2 Yb 3+ transition was also observed in the bulk and nanocrystalline samples following 488 nm excitation, thereby signifying the presence of an energy transfer process from Er 3+ to Yb 3+ . The peaks attributed to Yb 3+ emission were much less intense in the nanocrystalline material, indicating that the energy transfer process occurs less readily in this material because of the inherent high phonon energies from the adsorbed CO 2 and H 2 O on their surface. Following excitation with 978 nm, green and red anti-Stokes luminescence was evidenced in the samples under investigation. An enhancement of the red emission is observed in both bulk and nanocrystalline samples, although to a much greater degree in nanocrystalline Y 2 O 3:Er 3+, Yb 3+ . The enhancement of the red emission was shown to occur due to an ion-pair process of the form: ( 4 F 7/2, 4 I 11/2 ) → ( 4 F 9/2, 4 F 9/2 ), which directly populates the 4 F 9/2 state. However, this process cannot account for the drastic difference in the magnitude of the red enhancement between bulk and nanocrystalline samples. A phonon-assisted energy transfer process was found to be operative, which also populates the 4 F 9/2 state. This process occurs more readily in the nanocrystalline material as the large vibrational quanta from the adsorbed carbonate and hydroxyl ions can easily bridge the mismatch in energy.

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)0.003
metaresearch head score (Gemma)0.002
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
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 score0.013
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0030.002
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0000.001
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 head0.009
GPT teacher head0.231
Teacher spread0.222 · 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