Nanoscale Perspectives of Metal Degradation via In Situ Atom Probe Tomography

Lambeets, Sten; Kautz, Elizabeth J.; Wirth, Mark G.; Orren, Graham J.; Devaraj, Arun; Perea, Daniel E.

doi:10.1007/s11244-020-01367-z

Cited by 19 publications

(13 citation statements)

References 71 publications

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“…Furthermore, the development of methods based on multiple hit detection could be extended to the “operando” APT, allowing for an extension of the time resolution of the technique, which would no longer be limited by the pulse repetition frequency but rather by the temporal resolution of the detector. This may have a perspective application in the study of heterogeneous field-assisted catalysis …”

Section: Introductionmentioning

confidence: 99%

Surface Microscopy of Atomic and Molecular Hydrogen from Field-Evaporating Semiconductors

et al. 2021

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We report on the microscopic behavior of residual hydrogen on nanometric field emitters. By using homogeneous or heterostructured semiconductor specimens analyzed in a laser-assisted atom probe, it is possible to study how the relative abundances of the ionic species H+, H2 +, and H3 + depend on the microscopic electric field, estimated through post-ionization statistics. In the case of Ga-containing semiconductors, the relative abundances of H+, H2 +, and H3 + follow a common trend, independent of the nonmetallic component of the matrix. The dependence of the total H flux on the electric field exhibits a more complex behavior, which depends also on the spatial direction of the variation of the field (in-depth or on-surface). The analysis of multiple detection events provides further insights into surface chemistry. Noticeably, H+–H3 + ion pairs are both correlated in number and separated by very small distances on the detector space, suggesting a possible reaction 2H2 → H3 ++H++2e– taking place on the field emitter surface.

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Section: Introductionmentioning

confidence: 99%

Surface Microscopy of Atomic and Molecular Hydrogen from Field-Evaporating Semiconductors

et al. 2021

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“…The APT analysis was stopped after collecting 250 000 or 500 000 ions and the needle sample was transferred into the environmental reactor chamber attached to the APT vacuum system. [26,29] The oxidation experiments were conducted at 300 °C while 10 mbar oxygen with either natural-abundance or isotopically enriched 18 O 2 was flowed into the reactor chamber for specific time durations varying from 5 to 30 min. After the oxidation experiments, the samples were promptly transferred to the APT analysis chamber.…”

Section: Methodsmentioning

confidence: 99%

“…[11,12] In geological sciences mapping 18 O in solid minerals tracer and an environmental reactor chamber attached to the APT system. [26][27][28][29] We chose an austenitic Fe-18 wt% Cr-14 wt% Ni alloy because of its importance as a model alloy for stainless steels, which are widely used in everyday life and engineering applications because of their excellent mechanical properties and corrosion resistance. Despite the excellent corrosion resistance of stainless steels in ambient conditions, in applications such as nuclear reactors, stainless steels are subjected to higher temperatures up to 360 °C in pressurized water environments, where issues such as stress corrosion cracking (SCC) become serious concerns.…”

Section: Introductionmentioning

confidence: 99%

Visualizing the Nanoscale Oxygen and Cation Transport Mechanisms during the Early Stages of Oxidation of Fe–Cr–Ni Alloy Using In Situ Atom Probe Tomography

Devaraj

Barton

et al. 2022

Adv Materials Inter

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In forensics, 18 O mapping in materials can be instrumental for tracing geographical origins of animals and humans. [17] Among the different methods used to study the oxidation mechanisms in solid materials, in situ environmental transmission electron microscopy (TEM) and in situ scanning tunneling microscopy are powerful for studying the atomic-scale structural changes associated with the early stages of oxidation. [1,3,5,18,19] However, these in situ techniques lack the sensitivity to distinguish individual oxygen isotopes. At the same time, nanosecondary ion mass spectrometry (SIMS) and other massspectrometry-based techniques, which are highly sensitive for oxygen isotopes, lack 3D sub-nanometer-scale spatial resolutions. [14,17,20,21] Recently, ex situ atom probe tomography (APT) studies validated the ability of APT to achieve sub-nanometerscale spatially resolved mapping of 18 O isotope distribution in materials. [10,[22][23][24][25] However, expanding this ability of APT in mapping 18 O quantitatively at sub-nanometer scale spatial resolution toward in situ oxidation studies is yet to be demonstrated.Here, we demonstrate for the first time in situ APT analysis of oxygen diffusion in a model Fe-18 wt% Cr-14 wt% Ni model alloy (from here on called as Fe18Cr14Ni) using an 18 O isotopic Understanding the early stages of interactions between oxygen and material surfaces-especially at very high spatial resolutions-is highly beneficial for fields ranging from materials degradation, corrosion, geological sciences, forensics, and catalysis. The ability of in situ atom probe tomography (APT) is demonstrated to track the diffusion of oxygen and metal ions at nanoscale spatial resolution during the early stages of oxidation of a model Fe-Cr-Ni alloy. Using 18 O isotope tracers in these in situ APT experiments and complementary ex situ multimodal microscopy, spectroscopy, and computational simulations allows to precisely analyze the kinetics of oxidation and determine that outward cation diffusion to oxide/air interface is the primary mechanism for intragranular oxide growth in this alloy at 300 °C. This unique in situ isotopic tracer APT approach and the insights gained can be highly beneficial for studying early stages of gas-surface reactions in a broad array of materials.

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“…Cryogenic vacuum transfer systems for APT have been developed by several groups for in situ studies of environmentally-sensitive materials [ 7 – 10 ]. Integrated treatment cells have been developed to provide immediate APT analysis following a controlled exposure to gases at elevated temperatures [ 11 – 15 ]. Such platforms are capable of exposing materials to hydrogen/deuterium environments at high temperature and subsequently are cooled to freeze the charged structure.…”

Section: Introductionmentioning

confidence: 99%

Laser-equipped gas reaction chamber for probing environmentally sensitive materials at near atomic scale

et al. 2022

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Numerous metallurgical and materials science applications depend on quantitative atomic-scale characterizations of environmentally-sensitive materials and their transient states. Studying the effect upon materials subjected to thermochemical treatments in specific gaseous atmospheres is of central importance for specifically studying a material’s resistance to certain oxidative or hydrogen environments. It is also important for investigating catalytic materials, direct reduction of an oxide, particular surface science reactions or nanoparticle fabrication routes. This manuscript realizes such experimental protocols upon a thermochemical reaction chamber called the "Reacthub" and allows for transferring treated materials under cryogenic & ultrahigh vacuum (UHV) workflow conditions for characterisation by either atom probe or scanning Xe+/electron microscopies. Two examples are discussed in the present study. One protocol was in the deuterium gas charging (25 kPa D2 at 200°C) of a high-manganese twinning-induced-plasticity (TWIP) steel and characterization of the ingress and trapping of hydrogen at various features (grain boundaries in particular) in efforts to relate this to the steel’s hydrogen embrittlement susceptibility. Deuterium was successfully detected after gas charging but most contrast originated from the complex ion FeOD+ signal and the feature may be an artefact. The second example considered the direct deuterium reduction (5 kPa D2 at 700°C) of a single crystal wüstite (FeO) sample, demonstrating that under a standard thermochemical treatment causes rapid reduction upon the nanoscale. In each case, further studies are required for complete confidence about these phenomena, but these experiments successfully demonstrate that how an ex-situ thermochemical treatment can be realised that captures environmentally-sensitive transient states that can be analysed by atomic-scale by atom probe microscope.

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Nanoscale Perspectives of Metal Degradation via In Situ Atom Probe Tomography

Cited by 19 publications

References 71 publications

Surface Microscopy of Atomic and Molecular Hydrogen from Field-Evaporating Semiconductors

Surface Microscopy of Atomic and Molecular Hydrogen from Field-Evaporating Semiconductors

Visualizing the Nanoscale Oxygen and Cation Transport Mechanisms during the Early Stages of Oxidation of Fe–Cr–Ni Alloy Using In Situ Atom Probe Tomography

Laser-equipped gas reaction chamber for probing environmentally sensitive materials at near atomic scale

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