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Record W2039884003 · doi:10.1021/jp808341k

Specific Heat, Melting, Crystallization, and Oxidation of Zinc Nanoparticles and Their Transmission Electron Microscopy Studies

2008· article· en· W2039884003 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 C · 2008
Typearticle
Languageen
FieldEarth and Planetary Sciences
Topicnanoparticles nucleation surface interactions
Canadian institutionsMcMaster University
Fundersnot available
KeywordsNucleationCrystallizationTransmission electron microscopyZincMaterials scienceNanoparticleSupercoolingMelting pointEnthalpyGibbs free energyChemical engineeringCrystallographyAnalytical Chemistry (journal)ThermodynamicsChemistryNanotechnologyMetallurgyComposite material

Abstract

fetched live from OpenAlex

The specific heat, C p, of zinc nanoparticles (size distribution 30−180 nm and peak at 30 nm) was measured, and their melting behavior was investigated as the ZnO shell grew around the metal particles and thickened. Both structural and chemical analyses were performed by using Transmission Electron Microscopy and techniques of energy filtering and energy dispersive X-ray analyses. The C p of Zn nanoparticles is slightly higher than that of bulk metal. The melting point of Zn nanocrystals confined to the ZnO shell is only 1−2 K less than that of bulk Zn, much less than that expected from the Gibbs−Thomson equation. This is attributed to the increase in pressure on the zinc core because (i) zinc expands more on heating and on melting than ZnO, (ii) the ZnO shell thickens at the expense of the zinc core, and (iii) there is an epitaxial interaction between Zn and the ZnO shell. The enthalpy of melting decreases on thermal cycling. Nanodroplets of Zn supercooled by a few degrees before crystallizing in two steps. The high temperature step is attributed to heterogeneous nucleation at the core−shell interface, and the low temperature step to homogeneous nucleation in the particle core. The amount crystallized on homogeneous nucleation decreased on thermal cycling as the ZnO shell thickened when oxygen diffused through this layer. The enthalpy of crystallization also decreased on thermal cycling.

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 score0.006
Threshold uncertainty score0.177

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 head0.018
GPT teacher head0.258
Teacher spread0.240 · 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