Fracturing a nanoparticle

Abstract

Conventional wisdom and indirect studies suggest that the mechanical properties of nanoparticles can be considerably different than their bulk properties would predict. However, little is actually known about their mechanical behaviour because of the practical difficulties in investigating individual particles. Direct experimental studies of these properties require knowledge of the crystallographic orientation, size and microstructure of the nanoparticle in order to be complete. By deforming a single nanoparticle in the transmission electron microscope we have been able to determine each of these parameters of an isolated silicon nanoparticle a priori. With this approach, we could then directly examine dynamic deformation processes and demonstrate the first direct observation of plasticity-induced cleavage fracture of a silicon nanoparticle in compression.

Correlation of Enhanced Strength and Internal Structure for Heat‐Treated Submicron Stöber Silica Particles

“…In situ SEM and TEM studies have seen significant attention over the past years (see, e.g., refs.43,44 and literature therein). However, mechanical properties of single micron to submicron particles are widely unknown: studies conducted so far were either mainly of a qualitative nature, dedicated to only certain material properties, or an insufficient number of individual particles have been tested for proper statistical validation . For SFB particles (or similar materials) in particular, the number of studies on mechanical properties is limited.…”

Hardness and Elastic Modulus on Six-Fold Symmetry Gold Nanoparticles

“…All measurements were performed using Continuous Stiffness Measurement (CSM) method as described by Li et al [15]. …”

“…In order to record direction of dislocation, as presented by others Casillas [7], Ferreira [8] and Deneen [15], when using electron microscopy techniques, no further discussion can be made about dislocations, stacking faults, bulk phase change and twin boundaries on this systems of nanoparticles. …”

“…Unfortunately, the nanoindenter equipment used to perform measurements is not equipped with an imaging interface, which is needed to detect any microstructural change due to external forces. Therefore, a detailed understanding of atomistic behavior is not presented here, as it is presented in literature [8,15,19]. A trivial conclusion could be the formation of stacking faults and dislocations preferentially on the <111> direction of nanoparticles.…”

Evaluation of Force Fields for Molecular Dynamics Simulations of Platinum in Bulk and Nanoparticle Forms

“…However, to prevent sintering, the maximum load achieved with this method is limited, and the stress cannot be calculated directly, instead it is inferred from lattice changes. Separate in situ studies on the compression of silicon [31] and gold [18] nanoparticles using transmission electronic microscopy (TEM)-atomic force microscopy (AFM) have characterized reversible and irreversible deformation, as well as hardening-deformation relationships. But, these experiments are limited by AFM tip tilting, slip off of the nanoparticle from the tip, and lack of controllable strain rate.…”