Instable Microdeformation and Strain Recovery in Amorphous LiPON Thin Layer.

Lithium phosphorus oxynitride (LiPON) is a crucial electrolyte for all-solid-state thin-film batteries due to its sufficient ionic conductivity. Understanding the mechanical behavior of LiPON films is crucial for further technological development. Previous studies noted unexpected ductility and strain recovery in amorphous LiPON during sharp-ended tip indentations revealing pile-up formation and densification as the main deformation mechanisms.

Dislocation avalanches are like earthquakes on the micron scale.

Compression experiments on micron-scale specimens and acoustic emission (AE) measurements on bulk samples revealed that the dislocation motion resembles a stick-slip process - a series of unpredictable local strain bursts with a scale-free size distribution. Here we present a unique experimental set-up, which detects weak AE waves of dislocation slip during the compression of Zn micropillars. Profound correlation is observed between the energies of deformation events and the emitted AE signals that, as we conclude, are induced by the collective dissipative motion of dislocations.

Evolution of dislocation microstructure in irradiated Zr alloys determined by X-ray peak profile analysis.

During neutron irradiation of metals, owing to the enhanced number of vacancies and interstitial atoms, the climb motion of dislocations becomes significant at room temperature, leading to a recrystallization of the material. Moreover, the vacancies and interstitial atoms tend to form prismatic dislocation loops that play a crucial role in the plastic properties of the materials. X-ray peak profile analysis is an efficient nondestructive method to determine the properties of dislocation microstructure.

Micron-Scale Deformation: A Coupled In Situ Study of Strain Bursts and Acoustic Emission.

Plastic deformation of micron-scale crystalline materials differs considerably from bulk samples as it is characterized by stochastic strain bursts. To obtain a detailed picture of the intermittent deformation phenomena, numerous micron-sized specimens must be fabricated and tested. An improved focused ion beam fabrication method is proposed to prepare non-tapered micropillars with excellent control over their shape.

Scale-free phase field theory of dislocations.

According to recent experimental and numerical investigations, if a characteristic length (such as grain size) of a specimen is in the submicron size regime, several new interesting phenomena emerge during the deformation. Since in such systems boundaries play a crucial role, to model the plastic response it is crucial to determine the dislocation distribution near the boundaries. In this Letter, a phase-field-type continuum theory of the time evolution of an ensemble of parallel edge dislocations with identical Burgers vectors, corresponding to the dislocation geometry near internal boundaries, is presented.