Interdiffusion in bimetallic Au–Fe nanowhiskers controlled by interface mobility

TY - JOUR

T1 - Interdiffusion in bimetallic Au–Fe nanowhiskers controlled by interface mobility

AU - Qi, Yuanshen

AU - Richter, Gunther

AU - Suadiye, Eylül

AU - Klinger, Leonid

AU - Rabkin, Eugen

N1 - Publisher Copyright: © 2020

PY - 2020/9/15

Y1 - 2020/9/15

N2 - Nanoscale interdiffusion at the heterophase interfaces is the elementary process that controls solid-solid phase transformations and intermixing in multilayers. Here, we provide a direct experimental proof that the nanoscale multiphase interdiffusion is controlled by the interface mobility. We observed the anisotropic diffusion intermixing in Au–Fe bimetallic nanowhiskers, where the diffusion penetration depth of Fe into single crystalline Au nanowhisker across the incoherent Au–Fe interface was much greater than across its coherent counterpart. By applying a simple kinetic model to the results of diffusion measurements, we obtained the absolute values of mobilities of coherent and incoherent Fe-Au interfaces, and the Arrhenius parameters describing their temperature dependence. Atomic resolution scanning transmission electron microscopy confirmed that the lower mobility of the coherent interface is associated with the difficulties of the nucleation of interface disconnections. We proposed that the sluggish movement of the latter represents a kinetic “bottleneck” which determines the rate of intermixing. Our results indicate that the anisotropy of interface mobilities is a leading factor determining the anisotropic shape of precipitates formed in many heterogeneous solid-solid phase transformations.

AB - Nanoscale interdiffusion at the heterophase interfaces is the elementary process that controls solid-solid phase transformations and intermixing in multilayers. Here, we provide a direct experimental proof that the nanoscale multiphase interdiffusion is controlled by the interface mobility. We observed the anisotropic diffusion intermixing in Au–Fe bimetallic nanowhiskers, where the diffusion penetration depth of Fe into single crystalline Au nanowhisker across the incoherent Au–Fe interface was much greater than across its coherent counterpart. By applying a simple kinetic model to the results of diffusion measurements, we obtained the absolute values of mobilities of coherent and incoherent Fe-Au interfaces, and the Arrhenius parameters describing their temperature dependence. Atomic resolution scanning transmission electron microscopy confirmed that the lower mobility of the coherent interface is associated with the difficulties of the nucleation of interface disconnections. We proposed that the sluggish movement of the latter represents a kinetic “bottleneck” which determines the rate of intermixing. Our results indicate that the anisotropy of interface mobilities is a leading factor determining the anisotropic shape of precipitates formed in many heterogeneous solid-solid phase transformations.

KW - Electron microscopy

KW - Interdiffusion

KW - Interface migration

KW - Kinetics of phase transformations

KW - Nanowhiskers

UR - http://www.scopus.com/inward/record.url?scp=85088650849&partnerID=8YFLogxK

U2 - 10.1016/j.actamat.2020.07.041

DO - 10.1016/j.actamat.2020.07.041

M3 - 文章

AN - SCOPUS:85088650849

SN - 1359-6454

VL - 197

SP - 137

EP - 145

JO - Acta Materialia

JF - Acta Materialia

ER -