Investigating local oxidation processes in Fe thin films in a water vapor environment by in situ liquid cell TEM

Jordan W. Key; Shixiang Zhu; Christopher M. Rouleau; Raymond R. Unocic; Yao Xie; Josh Kacher

doi:10.1016/j.ultramic.2019.112842

Investigating local oxidation processes in Fe thin films in a water vapor environment by in situ liquid cell TEM

Jordan W. Key, Shixiang Zhu, Christopher M. Rouleau, Raymond R. Unocic, Yao Xie, Josh Kacher

Research output: Contribution to journal › Article › peer-review

15 Scopus citations

Abstract

Automated image recognition and analysis techniques were combined with liquid cell transmission electron microscopy to explore the oxidation kinetics of nanocrystalline Fe thin films in a water vapor environment. From in situ microscopy experiments, localized oxidation was observed to initiate in the film then propagate in an unsteady fashion, alternatingly arresting and progressing. The oxidation front propagation occurred via new oxidation sites initiating 10s of nm ahead of the existing front rather than through a continuous expansion mechanism. The oxidation rate was seen to be highly dependent on electron dose rate, with increasing electron dose rate accelerating the oxidation front propagation and increasing the density of oxidation initiation sites. The in situ experiments were also performed in diffraction space where it was seen that Fe₂O₃ was formed during oxidation. Coupling in situ microscopy with automated image analysis creates new opportunities for studying the early stages of localized corrosion by providing direct observation of oxidation propagation as well as quantification of the oxidation rates and rapid identification of byproducts.

Original language	English
Article number	112842
Journal	Ultramicroscopy
Volume	209
DOIs	https://doi.org/10.1016/j.ultramic.2019.112842
State	Published - Feb 2020

Funding

We gratefully acknowledge funding from the US Office of Naval Research under Grant No. N00014-17-1-2646. A portion of this work was completed using support from the Institute of Materials at Georgia Tech. The film deposition and in situ TEM corrosion experiments were conducted at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences (CNMS), which is a U.S. Department of Energy, Office of Science User Facility. Water vapor pressure calculations were performed by Dr. Kinga A. Unocic. We gratefully acknowledge funding from the US Office of Naval Research under Grant No. N00014-17-1-2646 . A portion of this work was completed using support from the Institute of Materials at Georgia Tech. The film deposition and in situ TEM corrosion experiments were conducted at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences (CNMS), which is a U.S. Department of Energy, Office of Science User Facility. Water vapor pressure calculations were performed by Dr. Kinga A. Unocic.

Keywords

Image processing
Liquid cell TEM
Oxidation
in situ TEM

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10.1016/j.ultramic.2019.112842

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title = "Investigating local oxidation processes in Fe thin films in a water vapor environment by in situ liquid cell TEM",

abstract = "Automated image recognition and analysis techniques were combined with liquid cell transmission electron microscopy to explore the oxidation kinetics of nanocrystalline Fe thin films in a water vapor environment. From in situ microscopy experiments, localized oxidation was observed to initiate in the film then propagate in an unsteady fashion, alternatingly arresting and progressing. The oxidation front propagation occurred via new oxidation sites initiating 10s of nm ahead of the existing front rather than through a continuous expansion mechanism. The oxidation rate was seen to be highly dependent on electron dose rate, with increasing electron dose rate accelerating the oxidation front propagation and increasing the density of oxidation initiation sites. The in situ experiments were also performed in diffraction space where it was seen that Fe2O3 was formed during oxidation. Coupling in situ microscopy with automated image analysis creates new opportunities for studying the early stages of localized corrosion by providing direct observation of oxidation propagation as well as quantification of the oxidation rates and rapid identification of byproducts.",

keywords = "Image processing, Liquid cell TEM, Oxidation, in situ TEM",

author = "Key, \{Jordan W.\} and Shixiang Zhu and Rouleau, \{Christopher M.\} and Unocic, \{Raymond R.\} and Yao Xie and Josh Kacher",

note = "Publisher Copyright: {\textcopyright} 2019 Elsevier B.V.",

year = "2020",

month = feb,

doi = "10.1016/j.ultramic.2019.112842",

language = "English",

volume = "209",

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T1 - Investigating local oxidation processes in Fe thin films in a water vapor environment by in situ liquid cell TEM

AU - Key, Jordan W.

AU - Zhu, Shixiang

AU - Rouleau, Christopher M.

AU - Unocic, Raymond R.

AU - Xie, Yao

AU - Kacher, Josh

PY - 2020/2

Y1 - 2020/2

N2 - Automated image recognition and analysis techniques were combined with liquid cell transmission electron microscopy to explore the oxidation kinetics of nanocrystalline Fe thin films in a water vapor environment. From in situ microscopy experiments, localized oxidation was observed to initiate in the film then propagate in an unsteady fashion, alternatingly arresting and progressing. The oxidation front propagation occurred via new oxidation sites initiating 10s of nm ahead of the existing front rather than through a continuous expansion mechanism. The oxidation rate was seen to be highly dependent on electron dose rate, with increasing electron dose rate accelerating the oxidation front propagation and increasing the density of oxidation initiation sites. The in situ experiments were also performed in diffraction space where it was seen that Fe2O3 was formed during oxidation. Coupling in situ microscopy with automated image analysis creates new opportunities for studying the early stages of localized corrosion by providing direct observation of oxidation propagation as well as quantification of the oxidation rates and rapid identification of byproducts.

AB - Automated image recognition and analysis techniques were combined with liquid cell transmission electron microscopy to explore the oxidation kinetics of nanocrystalline Fe thin films in a water vapor environment. From in situ microscopy experiments, localized oxidation was observed to initiate in the film then propagate in an unsteady fashion, alternatingly arresting and progressing. The oxidation front propagation occurred via new oxidation sites initiating 10s of nm ahead of the existing front rather than through a continuous expansion mechanism. The oxidation rate was seen to be highly dependent on electron dose rate, with increasing electron dose rate accelerating the oxidation front propagation and increasing the density of oxidation initiation sites. The in situ experiments were also performed in diffraction space where it was seen that Fe2O3 was formed during oxidation. Coupling in situ microscopy with automated image analysis creates new opportunities for studying the early stages of localized corrosion by providing direct observation of oxidation propagation as well as quantification of the oxidation rates and rapid identification of byproducts.

KW - Image processing

KW - Liquid cell TEM

KW - Oxidation

KW - in situ TEM

UR - https://www.scopus.com/pages/publications/85074557962

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DO - 10.1016/j.ultramic.2019.112842

M3 - Article

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AN - SCOPUS:85074557962

SN - 0304-3991

VL - 209

JO - Ultramicroscopy

JF - Ultramicroscopy

M1 - 112842

ER -

Investigating local oxidation processes in Fe thin films in a water vapor environment by in situ liquid cell TEM

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Keywords

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