Extreme lowering of the Debye temperature of Sn nanoclusters embedded in thermally grown<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">Si</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>by low-lying vibrational surface modes

Germanium nanoparticles embedded within dielectric matrices hold much promise for applications in optoelectronic and electronic devices. Here we investigate the formation of Ge nanoparticles in amorphous SiO 1.67 N 0.14 as a function of implanted atom concentration and thermal annealing temperature. Using x-ray absorption spectroscopy and other complementary techniques, we show Ge nanoparticles exhibit significant finite-size effects such that the coordination number decreases and structural disorder increases as the nanoparticle size decreases. While the composition of SiO 1.67 N 0.14 is close to that of SiO 2 , we demonstrate that the addition of this small fraction of N yields a much reduced nanoparticle size relative to those formed in SiO 2 under comparable implantation and annealing conditions. We attribute this difference to an increase in an atomic density and a much reduced diffusivity of Ge in the oxynitride matrix. These results demonstrate the potential for tailoring Ge nanoparticle sizes and structural properties in the SiO x N y matrices by controlling the oxynitride stoichiometry. V C 2015 AIP Publishing LLC. [http://dx.

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“…Similar observations have been reported for Ge NPs formed in SiO 2 . 29,34 Acquiring the spectra at the energy of 4. Table I.…”

Section: Resultsmentioning

confidence: 99%

Formation of Ge nanoparticles in SiOxNy by ion implantation and thermal annealing

Mirzaei

Kremer

Sprouster

et al. 2015

Journal of Applied Physics

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“…5,7 Several aspects of the thermodynamics of nanosized particles remain unclear. In recent literature, Θ D of nanoparticles (NP) has been reported to be lower, 8,9 similar, 2,10,11 or even higher 12,13 than the corresponding one for bulk systems. However, the different environment of the NP in each case makes it difficult to establish a direct comparison between those experiments to determine a general characteristic for nanoparticles.…”

Section: Introductionmentioning

confidence: 98%

“…In most of the published articles, the size distribution and the structural characterization of the NP were not accurately determined. 9 This makes it difficult to infer truthful correlations between size, structure, and basic properties, including thermodynamics, and more specifically the Debye temperature. Beni and Platzman 19 were the first to introduce this type of analysis.…”

Section: Introductionmentioning

confidence: 99%

Anomalous Vibrational Properties Induced by Surface Effects in Capped Pt Nanoparticles

et al. 2007

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The Debye temperature of Pt nanoparticles (NP) capped in PVP-K30 with an average diameter of 3 nm was determined from extended X-ray absorption fine structure measurements between 20 and 373 K. The size distribution of the NP was determined by high-resolution transmission electron microscopy, high-angle annular dark field, and small-angle X-ray scattering. We have experimentally established that the Debye temperature of truncated cuboctahedron, capped Pt NP is 70 K higher than that of bulk Pt metal. The rather high value of the Debye temperature of nanosized-capped Pt crystals is related to surface Pt−Pt contraction effects in conjunction with capping interactions. This finding evidences that the vibrational behavior of nanostructure materials differs markedly from that of materials in bulk form.

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“…[14], red and pink sphere represent experimental data and simulation results at 1000 K and 600 K, respectively [70]. Input parameters for Ag nanoparticles are given in Tables 1 and 2 Table 1 Bulk thermodynamic properties used in the models Element Melting temperature (K) [12] Cohesive energy (kJ/mol) [49] Debye temperature (K) [58,60,75] Thermal conductivity (W/m-K) [76,77] Electrical conductivity (Ω-m) −1 [78] Sp. heat capacity (J/mol-K) […”

Section: Discussionmentioning

confidence: 99%

“…(19). Wine and red solid sphere represent experimental and simulation results for Co [58], orange sphere represents experimental results for Au [59] and pink sphere represents experimental results for Sn [60]. Input parameters for Au are given in Tables 1 and 2 Prediction of the present model along with experimental results for Ag nanoparticles is shown in Fig.…”

Section: Thermal Conductivitymentioning

confidence: 99%

Modelling of size-dependent thermodynamic properties of metallic nanocrystals based on modified Gibbs–Thomson equation

Ansari

2021

Appl. Phys. A

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In this paper, a new theoretical two-phase (solid–liquid) type model of melting temperature has developed based on the modified Gibbs–Thomson equation. Further, it is extended to derive other different size-dependent thermodynamic properties such as cohesive energy, Debye temperature, specific heat capacity, the thermal and electrical conductivity of metallic nanoparticles. Quantitative calculation of the effect of size on thermodynamic properties resulted in, varying linearly with the inverse of characteristic length of nanomaterials. The models are applied to Al, Pb, Ag, Sn, Mo, W, Co, Au and Cu nanoparticles of spherical shape. The melting temperature, Debye temperature, thermal and electrical conductivity are found to decrease with the decrease in particle size, whereas the cohesive energy and specific heat capacity are increased with the decrease in particle size. The present model is also compared with previous models and found consistent. The results obtained with this model validated with experimental and simulation results from several sources that show similar trends between the model and experimental results. Graphic abstract

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Extreme lowering of the Debye temperature of Sn nanoclusters embedded in thermally grownSiO2by low-lying vibrational surface modes

Cited by 18 publications

References 34 publications

Formation of Ge nanoparticles in SiOxNy by ion implantation and thermal annealing

Formation of Ge nanoparticles in SiOxNy by ion implantation and thermal annealing

Anomalous Vibrational Properties Induced by Surface Effects in Capped Pt Nanoparticles

Modelling of size-dependent thermodynamic properties of metallic nanocrystals based on modified Gibbs–Thomson equation

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