Melting of Pb nanocrystals

Peters, Kevin F.; Cohen, J. B.; Chung, Yip‐Wah

doi:10.1103/physrevb.57.13430

Cited by 235 publications

(182 citation statements)

References 59 publications

Supporting

Mentioning

166

Contrasting

Unclassified

Order By: Relevance

“…Some phenomenological models of melting of free nanoparticles employed the effect of surface melting inherent in the most solids. For example, the liquid-layer model [2,21] postulates formation of a quasi-liquid layer at the surface of a nanocrystal at temperature below its melting point.…”

Section: Introductionmentioning

confidence: 99%

Melting and thermodynamic properties of rare gas nanocrystals

Karasevskii

Lubashenko

2009

Low Temperature Physics

View full text Add to dashboard Cite

A self-consistent statistical method [Phys. Rev. B66, 054302 (2002)] is used to describe thermodynamic properties of free rare gas nanocrystals using thin plates as examples. It is shown that size influence on thermodynamic properties of nanocrystals is caused by size-dependent quantization of the vibration spectrum affecting the parameters of a statistical distribution function of atomic displacements and, thus, governing size dependence of average values of energetic contributions to the Gibbs free energy of the system. For Xe nanocrystals, we present calculated size dependences of the Debye temperature, heat capacity, interatomic distance, melting temperature, etc. PACS: 64.70.D-Solid-liquid transitions;65.80.+n Thermal properties of small particles, nanocrystals, and nanotubes.

show abstract

Section: Introductionmentioning

confidence: 99%

Melting and thermodynamic properties of rare gas nanocrystals

Karasevskii

Lubashenko

2009

Low Temperature Physics

View full text Add to dashboard Cite

show abstract

“…The formation of a liquid outer shell is something that has been observed in static experiments (12) but has yet to be confirmed on a picosecond timescale. It is speculated that for temperatures below the melting temperature, the process of liquid-shell formation is reversible (5,9,12). However, this is still largely unconfirmed and the degree of reversibility is still an open question.…”

mentioning

confidence: 85%

“…It has also been suggested that raising the temperature of nanoparticles to 100°C can facilitate surface premelting (10). The formation of a liquid outer shell is something that has been observed in static experiments (12) but has yet to be confirmed on a picosecond timescale. It is speculated that for temperatures below the melting temperature, the process of liquid-shell formation is reversible (5,9,12).…”

mentioning

confidence: 91%

Imaging transient melting of a nanocrystal using an X-ray laser

Clark

Beitra

Xiong

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

There is a fundamental interest in studying photoinduced dynamics in nanoparticles and nanostructures as it provides insight into their mechanical and thermal properties out of equilibrium and during phase transitions. Nanoparticles can display significantly different properties from the bulk, which is due to the interplay between their size, morphology, crystallinity, defect concentration, and surface properties. Particularly interesting scenarios arise when nanoparticles undergo phase transitions, such as melting induced by an optical laser. Current theoretical evidence suggests that nanoparticles can undergo reversible nonhomogenous melting with the formation of a core-shell structure consisting of a liquid outer layer. To date, studies from ensembles of nanoparticles have tentatively suggested that such mechanisms are present. Here we demonstrate imaging transient melting and softening of the acoustic phonon modes of an individual gold nanocrystal, using an X-ray free electron laser. The results demonstrate that the transient melting is reversible and nonhomogenous, consistent with a core-shell model of melting. The results have implications for understanding transient processes in nanoparticles and determining their elastic properties as they undergo phase transitions.X-ray laser | coherent diffraction | phase transition | ultrafast imaging | pump-probe N anoparticles also display interesting properties due to their size and morphology; for example, they can exhibit anomalously low thermal conductivity due to the phonon mean free path approaching the size of the particle. This has significant implications for developing novel thermoelectric devices (1). Further interest in transient processes in nanoparticles comes from their role in photoacoustic imaging (2) and photothermal cancer therapy (3) and their potential in high-harmonic generation (4). Therefore, it is critical from both a fundamental and a practical point of view to understand the photon, electron, and lattice interactions of nanoparticles irradiated with a short pulse (<100 fs) laser up to the point of melting.Molecular dynamics (MD) simulations have provided the most detailed models of the nanoparticles' response to laser irradiation at low intensity, with reversible nonhomogenous surface premelting predicted (5, 6). The simulations indicated that isolated regions on the nanoparticle surface begin to melt before forming a continuous layer. Additionally, these simulations suggest that before the formation of a nonhomogenous liquid outer layer surrounding a solid inner core, preferential facet premelting can occur with liquid-like atoms appearing first in the (100) and (110) crystallographic directions. It was also observed that during the formation of the liquid outer layer, liquid regions extended inward toward the solid core. Simulations on larger nanorods (7) have suggested more exotic behavior during laser-induced premelting, such as internal structural changes from face-centered cubic to hexagonal close-packed structures along with the for...

show abstract

“…Two abovementioned stages are the surface premelting and the thermodynamically described melting [3], [7]. Such a classi¯cation seems somewhat incorrect as, in principle, thermodynamics also predicts the°at-surface premelting when the condition…”

Section: Introductionmentioning

confidence: 99%

“…According to [7], all the available theories of the small-particle melting may be reduced to three basic models: homogeneous melting model without a liquid skin; liquid skin melting model; and liquid nucleation and growth model with unstable liquid skin.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic model of crystallization and melting of small particles

Samsonov

Malkov

2004

Open Physics

View full text Add to dashboard Cite

Abstract:The size dependence of the nanocrystal melting temperature has been investigated based on a nonequilibrium thermodynamics approach. An expression has been derived for the melting temperature that, contrary to the classical Tomson formula, takes into account the metastable character of the crystal nucleus-melt shell equilibrium. Quantitative estimations have been carried out for small spherical particles of aluminum, tin, and lead.

show abstract

Melting of Pb nanocrystals

Cited by 235 publications

References 59 publications

Melting and thermodynamic properties of rare gas nanocrystals

Melting and thermodynamic properties of rare gas nanocrystals

Imaging transient melting of a nanocrystal using an X-ray laser

Thermodynamic model of crystallization and melting of small particles

Contact Info

Product

Resources

About