Three-dimensional imaging of dislocation dynamics during the hydriding phase transformation

被引：2

作者：

Ulvestad, A. ^{[1
]}

Welland, M. J. ^{[2
]}

Cha, W. ^{[1
]}

Liu, Y. ^{[1
]}

Kim, J. W. ^{[3
]}

Harder, R. ^{[3
]}

Maxey, E. ^{[3
]}

Clark, J. N. ^{[4
]}

Highland, M. J. ^{[1
]}

You, H. ^{[1
]}

Zapol, P. ^{[1
]}

Hruszkewycz, S. O. ^{[1
]}

Stephenson, G. B. ^{[1
]}

机构：

[1] Argonne Natl Lab, Mat Sci Div, Argonne, IL 60439 USA

[2] Canadian Nucl Labs, Fuel & Fuel Channel Safety Branch, Chalk River, ON K0J 1J0, Canada

[3] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA

[4] Stanford PULSE Inst, SLAC Natl Accelerator Lab, Menlo Pk, CA 94025 USA

来源：

NATURE MATERIALS | 2017年 / 16卷 / 05期

关键词：

X-RAY-DIFFRACTION; INDIVIDUAL PALLADIUM NANOPARTICLES; OPEN 2-PHASE SYSTEMS; COHERENT INTERFACES; STRAIN; HYDROGEN; NANOCRYSTALS; THERMODYNAMICS; NANOSCALE; MICROSCOPY;

D O I：

10.1038/NMAT4842

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Crystallographic imperfections significantly alter material properties and their response to external stimuli, including solute-induced phase transformations. Despite recent progress in imaging defects using electron and X-ray techniques, in situ three-dimensional imaging of defect dynamics remains challenging. Here, we use Bragg coherent diffractive imaging to image defects during the hydriding phase transformation of palladium nanocrystals. During constant-pressure experiments we observe that the phase transformation begins after dislocation nucleation close to the phase boundary in particles larger than 300 nm. The three-dimensional phase morphology suggests that the hydrogen-rich phase is more similar to a spherical cap on the hydrogen-poor phase than to the core-shell model commonly assumed. We substantiate this using three-dimensional phase field modelling, demonstrating how phase morphology affects the critical size for dislocation nucleation. Our results reveal how particle size and phase morphology affects transformations in the PdH system.

引用

页码：565 / +

页数：9