Analysis of Ni nanoparticle gas phase sintering

Tsyganov, Sergej; Kästner, J.; Rellinghaus, Bernd; Kauffeldt, Thomas; Westerhoff, F.; Wolf, Dietrich E.

doi:10.1103/physrevb.75.045421

Cited by 49 publications

(57 citation statements)

References 28 publications

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“…Tsyganov et al experimentally studied the sintering of Ni nanoparticle agglomerates in the gas phase. 29 They showed a series of transmission electron microscopy micrographs of particle agglomerates which have been sintered for 7 s at temperatures in the range between 300 and 1073 K. They observe that with increasing temperature the necks between the primaries vanish, similar to our observation in Fig. 6͑b͒.…”

Section: A Short Chain Aggregatessupporting

confidence: 79%

Molecular dynamics simulation and continuum modeling of straight-chain aggregate sintering: Development of a phenomenological scaling law

Hawa

Zachariah

2007

Phys. Rev. B

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Atomistic molecular dynamics simulation and a simple continuum viscous flow model are employed to investigate the sintering of straight-chain nanoparticle aggregates. The results are used to develop a phenomenological sintering scaling law. The chain aggregates investigated consist of up to 80 primary particles of silicon, with primary particles of 2.5-7 nm in diameter. We found that sintering of chain aggregates consists of three steps. In step ͑a͒, reaction between particles to minimize surface defects and development of a cylindrical like shape comprised an induction period.Step ͑b͒ consisted of contraction of the cylinder, which actually consisted of two contraction stages. The first stage was the local contraction stage where sintering occurs only at the ends of the particle chain, and the second stage involved the global contraction. The last step was the nominal sintering process from an oval to spherical shape. As expected, sintering time increases with increasing chain length, with the exception that very long chains fragmented. The sintering times normalized by the primary particle diameter showed a universal relationship which only depends on chain length. These results were found to be consistent with a mathematical model we develop based on continuum viscous flow. The model was able to predict the sintering time in excellent agreement with results obtained from molecular dynamics simulation for any chain length and any primary particle size for straight nanoparticle chain aggregates. The results for sintering times for aggregate chains could be summarized with a power law modification of the Frenkel viscous flow equation, to include a dependence on the number of particle connections in a chain aggregate: t = t Frenkel * ͑N −1͒ 0.68 .

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Section: A Short Chain Aggregatessupporting

confidence: 79%

Molecular dynamics simulation and continuum modeling of straight-chain aggregate sintering: Development of a phenomenological scaling law

Hawa

Zachariah

2007

Phys. Rev. B

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“…This indicates that surface diffusion is a main mechanism driving the coalescence process under the electron beam. This observation is in good agreement with previous works [48,49].…”

Section: Silver Nanoparticle Coalescencesupporting

confidence: 94%

Applying compressive sensing to TEM video: a substantial frame rate increase on any camera

Stevens

Kovařík

Abellán

et al. 2015

Adv Struct Chem Imag

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One of the main limitations of imaging at high spatial and temporal resolution during in-situ transmission electron microscopy (TEM) experiments is the frame rate of the camera being used to image the dynamic process. While the recent development of direct detectors has provided the hardware to achieve frame rates approaching 0.1 ms, the cameras are expensive and must replace existing detectors. In this paper, we examine the use of coded aperture compressive sensing (CS) methods to increase the frame rate of any camera with simple, low-cost hardware modifications. The coded aperture approach allows multiple sub-frames to be coded and integrated into a single camera frame during the acquisition process, and then extracted upon readout using statistical CS inversion. Here we describe the background of CS and statistical methods in depth and simulate the frame rates and efficiencies for in-situ TEM experiments. Depending on the resolution and signal/noise of the image, it should be possible to increase the speed of any camera by more than an order of magnitude using this approach. Mathematics Subject Classification: (2010) 94A08 · 78A15

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“…Surface diffusion is known to be an alternative mechanism that dominates Ni sintering at the nanoscale [26,27]. Thus, clarification of the role of surface diffusion at the sub-micron scale is important.…”

Section: Resultsmentioning

confidence: 99%

Sintering analysis of sub-micron-sized nickel powders: Kinetic Monte Carlo simulation verified by FIB–SEM reconstruction

Hara

Ohi

Shikazono

2015

Journal of Power Sources

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Since sintering of sub-micron-sized particles is a critical phenomenon affecting the electrochemical performance and reliability of solid oxide fuel cell systems, a better understanding of this microstructure-related process is of great importance. In this study, we show that kinetic Potts Monte Carlo modeling is capable of quantitatively predicting the three-dimensional (3D) microstructure evolution over an entire stage of nickel sintering at the sub-micron scale. This is achieved through direct comparison of simulation results and 3D microstructural analysis using focused ion beam-scanning electron microscopy. We show that grain boundary diffusion is the dominant mechanism on densification, while surface diffusion has an impact on the coarsening during sub-micron scale sintering, only acting as one of the multiple mechanisms of sintering.

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Analysis of Ni nanoparticle gas phase sintering

Cited by 49 publications

References 28 publications

Molecular dynamics simulation and continuum modeling of straight-chain aggregate sintering: Development of a phenomenological scaling law

Molecular dynamics simulation and continuum modeling of straight-chain aggregate sintering: Development of a phenomenological scaling law

Applying compressive sensing to TEM video: a substantial frame rate increase on any camera

Sintering analysis of sub-micron-sized nickel powders: Kinetic Monte Carlo simulation verified by FIB–SEM reconstruction

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