Reversible phase changes in Ge–Au nanoparticles

Guzman, J.; Boswell-Koller, Cosima N.; Beeman, J. W.; Bustillo, Karen C.; Conry, Thomas E.; Hansen, W. L.; Levander, A. X.; Liao, Chang; Lieten, Ruben; Sawyer, C. A.; Sherburne, Matthew; Shin, S. J.; Stone, Peter; Watanabe, Masashi; Yu, K. M.; Ager, Joel W.; Chrzan, D. C.; Häller, E. E.

doi:10.1063/1.3584850

Cited by 7 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4b), and each RTA step except the first taking an identical initial distribution and thus returning an identical final distribution. This result corresponds with recent experiments [3], which have shown that the process is repeatable in an AuGe alloy nanoparticle system with nanoparticles still present after ten PLM/RTA cycles, and suggests that no significant degradation in the size distribution will occur. It should be noted, however, that this result may be an artifact of the small interface energy; the smaller particle size means the laser is able to "reset" the distribution to a single peak of very small particles, while in a system with higher interface energy, some very large particles may survive the pulse and lead to a different distribution.…”

Section: Annealingsupporting

confidence: 91%

“…Just 100 ns after the laser pulse ends, the temperature of the implanted layer has dropped to 589 K, corresponding with experimental evidence of a fast quench rate [3]. Because of the relatively high thermal conductivity of silicon, the highest temperature the substrate reaches is 458 K at the surface.…”

Section: Resultsmentioning

confidence: 79%

“…Phase change applications require a method of reliably switching the material from one phase to the other. One such method is thermal; a fast quench from pulsed-laser melting (PLM) will produce amorphous particles while a slower rapid thermal anneal (RTA) will cause recrystallization [1,2,3]. In PLM, a short laser pulse produces rapid temperature rise in the sample, causing melting, dissolution, and/or coarsening of the nanoparticles; a quantitative understanding of this process will enable control and optimization of future devices.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Modeling pulsed-laser melting of embedded semiconductor nanoparticles

Sawyer

Guzman

Boswell-Koller

et al. 2011

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

Pulsed-laser melting (PLM) is commonly used to achieve a fast quench rate in both thin films and nanoparticles. A model for the size evolution during PLM of nanoparticles confined in a transparent matrix, such as those created by ion-beam synthesis, is presented. A self-consistent mean-field rate equations approach that has been used successfully to model ion beam synthesis of germanium nanoparticles in silica is extended to include the PLM process. The PLM model includes classical optical absorption, multiscale heat transport by both analytical and finite difference methods, and melting kinetics for confined nanoparticles. The treatment of nucleation and coarsening behavior developed for the ion beam synthesis model is modified to allow for a non-uniform temperature gradient and for interacting liquid and solid particles with different properties. The model allows prediction of the particle size distribution after PLM under various laser fluences, starting from any particle size distribution including as-implanted or annealed simulated samples. A route for narrowing the size distribution of embedded nanoparticles is suggested, with simulated distribution widths as low as 15% of the average size.

show abstract

Section: Annealingsupporting

confidence: 91%

Section: Resultsmentioning

confidence: 79%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling pulsed-laser melting of embedded semiconductor nanoparticles

Sawyer

Guzman

Boswell-Koller

et al. 2011

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Low eutectic point in Au 1−x Si x can fabricate easily on the a-Si film [19], a thin film of organic electroluminescence diode [20] and ZnO diode [21]. Other representative applications in nano-engineering, write-once optical disk [22] and rewritable data storage [23] were proposed.…”

Section: Introductionmentioning

confidence: 99%

Au Nanoparticle Formation from Amorphous Au/Si Multilayer

Aono¹,

Abe²,

Kobayashi³

2014

JCPT

View full text Add to dashboard Cite

By direct observations of transmission electron microscopy (TEM), irreversible morphological transformations of as-deposited amorphous Au/Si multilayer (a-Au/a-Si) were observed on heating. The well arrayed sequence of the multilayer changed to zigzag layered structure at 478 K (=T zig). Finally, the zigzag structure transformed to Au nanoparticles at 508 K. The distribution of the Au nanoparticles was random within the thin film. In situ X-ray diffraction during heating can clarify partial crystallization Si (c-Si) in the multilayer at 450 K (= T ML MIC), which corresponds to metal induced crystallization (MIC) from amorphous Si (a-Si) accompanying by Au diffusion. On further heating, a-Au started to crystallize at around 480 K (=T c) and gradually grew up to 3.2 nm in radius, although the volume of c-Si was almost constant. Continuous heating caused crystal Au (c-Au) melting into liquid AuSi (ℓ-AuSi) at 600 K (= T NP m), which was lower than bulk eutectic temperature (T B E = 636 5 K ±). Due to the AuSi eutectic effect, reversible phase transition between liquid and solid occurred once temperature is larger than T NP m. Proportionally to the maximum temperatures at each cycles (673, 873 and 1073 K), both T NP m and Au crystallization temperature approaches to T B E. Using a thermodynamic theory of the nanoparticle formation in the eutectic system, the relationship between T NP m and the nanoparticle size is explained.

show abstract

Eutectic Combinations as a Pathway to the Formation of Substrate‐Based Au‐Ge Heterodimers and Hollowed Au Nanocrescents with Tunable Optical Properties

Sundar

Farzinpour

Gilroy

et al. 2014

Small

View full text Add to dashboard Cite

Pairs of immiscible elements with deep eutectics are used to synthesize periodic arrays of heterodimers and hollowed metal nanocrescents. In the devised route, substrate-immobilized Au or Ag nanostructures act as heterogeneous nucleation sites for Ge adatoms. At elevated temperatures the adatoms collect in sufficient quantities to transform each site into a AuGe liquid alloy which, upon cooling, phase separates into elemental components sharing a common interface. The so-formed Au-Ge and Ag-Ge heterodimers exhibit a complex morphology characterized by a noble metal nanocrescent which partially encapsulates one end of the Ge domain. Through the use of a selective etch the Ge component is removed, leaving behind a periodic array of hollow noble metal nanocrescents on the surface of the substrate. Optical characterization of both the heterodimers and nanocrescents indicates that the presence of Ge gives rise to a relative blue-shift in the localized surface plasmon peak, a result that is in stark contrast to the red-shifts typically observed when plasmonic nanostructures are in contact with a dielectric medium. Simulations are used to both rationalize the observed shift and show the potential for deriving unexpected behaviors when semishell-like noble metal structures are in contact with high permittivity dielectric mediums.

show abstract

Reversible phase changes in Ge–Au nanoparticles

Cited by 7 publications

References 16 publications

Modeling pulsed-laser melting of embedded semiconductor nanoparticles

Modeling pulsed-laser melting of embedded semiconductor nanoparticles

Au Nanoparticle Formation from Amorphous Au/Si Multilayer

Eutectic Combinations as a Pathway to the Formation of Substrate‐Based Au‐Ge Heterodimers and Hollowed Au Nanocrescents with Tunable Optical Properties

Contact Info

Product

Resources

About