scholarly journals Study of the field evaporation mechanism of laser-assisted atom probe

2011 ◽  
Vol 17 (3) ◽  
pp. 224-226 ◽  
Author(s):  
Tetsuo Terakawa ◽  
Norihito Mayama ◽  
Yasuko Kajiwara ◽  
Masanori Owari
Keyword(s):  
Atom Probe ◽  
Field Evaporation ◽  
Evaporation Mechanism

scholarly journals Enhanced Atom Probe Imaging using Generalised Field Evaporation Models

2021 ◽  
Vol 27 (S1) ◽  
pp. 404-406
Author(s):  
Charles Fletcher ◽  
Michael Moody ◽  
Jeroen Scheerder ◽  
Claudia Fleischmann ◽  
Brian Geiser ◽  
...  
Keyword(s):  
Atom Probe ◽  
Field Evaporation ◽  
Evaporation Models

Understanding of Capping Effects on the Tip Shape Evolution and on the Atom Probe Data of Bulk LaAlO3 Using Transmission Electron Microscopy

2017 ◽  
Vol 23 (2) ◽  
pp. 329-335 ◽  
Author(s):  
Chang-Min Kwak ◽  
Young-Tae Kim ◽  
Chan-Gyung Park ◽  
Jae-Bok Seol
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atom Probe ◽  
Resolving Power ◽  
Shape Evolution ◽  
Oxide Materials ◽  
Field Evaporation ◽  
Laser Illumination ◽  
Transmission Electron ◽  
Mass Resolving Power

AbstractTwo challenges exist in laser-assisted atom probe tomography (APT). First, a drastic decline in mass-resolving power is caused, not only by laser-induced thermal effects on the APT tips of bulk oxide materials, but also the associated asymmetric evaporation behavior; second, the field evaporation mechanisms of bulk oxide tips under laser illumination are still unclear due to the complex relations between laser pulse and oxide materials. In this study, both phenomena were investigated by depositing Ni- and Co-capping layers onto the bulk LaAlO3 tips, and using stepwise APT analysis with transmission electron microscopy (TEM) observation of the tip shapes. By employing the metallic capping, the heating at the surface of the oxide tips during APT analysis became more symmetrical, thereby enabling a high mass-resolving power in the mass spectrum. In addition, the stepwise microscopy technique visualized tip shape evolution during APT analysis, thereby accounting for evaporation sequences at the tip surface. The combination of “capping” and “stepwise APT with TEM,” is applicable to any nonconductors; it provides a direct observation of tip shape evolution, allows determination of the field evaporation strength of oxides, and facilitates understanding of the effects of ultrafast laser illumination on an oxide tip.

scholarly journals Automated Atom-By-Atom Three-Dimensional (3D) Reconstruction of Field Ion Microscopy Data

2017 ◽  
Vol 23 (2) ◽  
pp. 255-268 ◽  
Author(s):  
Michal Dagan ◽  
Baptiste Gault ◽  
George D. W. Smith ◽  
Paul A. J. Bagot ◽  
Michael P. Moody
Keyword(s):  
Three Dimensional ◽  
Reconstruction Algorithm ◽  
Automated Analysis ◽  
Atom Probe ◽  
Crystal Defects ◽  
Steel Matrix ◽  
Field Evaporation ◽  
Field Ion Microscopy ◽  
Ion Microscopy ◽  
Microscopy Data

AbstractAn automated procedure has been developed for the reconstruction of field ion microscopy (FIM) data that maintains its atomistic nature. FIM characterizes individual atoms on the specimen’s surface, evolving subject to field evaporation, in a series of two-dimensional (2D) images. Its unique spatial resolution enables direct imaging of crystal defects as small as single vacancies. To fully exploit FIM’s potential, automated analysis tools are required. The reconstruction algorithm developed here relies on minimal assumptions and is sensitive to atomic coordinates of all imaged atoms. It tracks the atoms across a sequence of images, allocating each to its respective crystallographic plane. The result is a highly accurate 3D lattice-resolved reconstruction. The procedure is applied to over 2000 tungsten atoms, including ion-implanted planes. The approach is further adapted to analyze carbides in a steel matrix, demonstrating its applicability to a range of materials. A vast amount of information is collected during the experiment that can underpin advanced analyses such as automated detection of “out of sequence” events, subangstrom surface displacements and defects effects on neighboring atoms. These analyses have the potential to reveal new insights into the field evaporation process and contribute to improving accuracy and scope of 3D FIM and atom probe characterization.

Laser-Assisted Field Evaporation of (R = Gd, Sm) High-Temperature Superconducting Coated Conductors

2021 ◽  
pp. 1-18
Author(s):  
Jesse D. Smith ◽  
Jeong Huh ◽  
Adam Shelton ◽  
Richard F. Reidy ◽  
Marcus L. Young
Keyword(s):  
High Temperature ◽  
High Temperature Superconductors ◽  
Compositional Analysis ◽  
Atom Probe ◽  
Fracture Probability ◽  
Coated Conductors ◽  
Field Evaporation ◽  
Laser Absorption ◽  
New Instrument ◽  
New Perspective

In the field of high-temperature superconductors, atom probe tomography is a relatively new instrument, with the ability to provide a new perspective on the 3D nanoscale microstructure. However, field evaporation of nonmetallic materials is fraught with unique challenges that matter little in the world of metallic evaporation. In this study, we review the laser absorption, correlated evaporation, molecular dissociation, and the crystallographic effects on the field evaporation of 800-m ${\rm RB}{\rm a}_ 2{\rm C}{\rm u}_ 3{\rm O}_{ 7-{\rm \delta }}$ (R = Gd, Sm) coated conductor tapes deposited by Reactive Co-Evaporation Cyclic Deposition and Reaction (RCE-CDR). Ultraviolet 355 nm laser pulsing was found to have a substantial beneficial effect on minimizing the fracture probability compared with 532 nm illumination, especially when evaporating insulating oxide precipitates. This, in turn, allows for the 3D compositional analysis of defects such as flux pinning centers introduced by precipitation and doping. As a result, evidence for the precipitation of nanoscale ${\rm G}{\rm d}_ 2{\rm C}{\rm u}_ 2{\rm O}_ 5$ is discussed. The effect of crystallographic orientation is studied, where [001] aligned evaporation is found to develop compositional aberrations.

scholarly journals Spatial Resolution in the Atom Probe Field Ion Microscope

1997 ◽  
Vol 3 (S2) ◽  
pp. 1189-1190
Author(s):  
M. K. Miller
Keyword(s):  
Spatial Resolution ◽  
Atom Probe ◽  
Single Atom ◽  
Field Evaporation ◽  
Sensitive Detector ◽  
Probe Field ◽  
3 Dimensional ◽  
Number Of Factors ◽  
The Individual ◽  
Field Ion Microscope

The atom probe field ion microscope can resolve and identify individual atoms. This ability is demonstrated in a pair of field ion micrographs of an Ni3Al specimen, Fig. 1, in which the individual atoms on the close packed (111) plane are clearly resolved. Comparison of these two micrographs reveals that an individual atom was field evaporated between the micrographs. Due to the hemispherical nature of the specimen, the ability to resolve this two dimensional atomic arrangement is only possible on low index plane facets. The spatial resolution in field ion images is determined by a number of factors including specimen temperature, material, microstructural features, specimen geometry, and crystallographic location.The spatial resolution of the data obtained in atom probe and 3 dimensional atom probe compositional analyses can be evaluated with the use of field evaporation or field desorption images. The field evaporation images are formed from the surface atoms with the use of a single atom sensitive detector whereas the field ion image is formed from the projection of a continuous supply of ionized image gas atoms.

scholarly journals Atom probe tomography field evaporation characteristics and compositional corrections of ZrB2

2019 ◽  
Vol 156 ◽  
pp. 109871 ◽  
Author(s):  
David L.J. Engberg ◽  
Lina Tengdelius ◽  
Hans Högberg ◽  
Mattias Thuvander ◽  
Lars Hultman
Keyword(s):  
Atom Probe Tomography ◽  
Atom Probe ◽  
Field Evaporation

scholarly journals Field evaporation and atom probe tomography of pure water tips

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
T. M. Schwarz ◽  
E. M. Weikum ◽  
K. Meng ◽  
E. Hadjixenophontos ◽  
C. A. Dietrich ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Atom Probe Tomography ◽  
Pure Water ◽  
Biological Systems ◽  
Laser Pulses ◽  
Atom Probe ◽  
Virus Protein ◽  
Field Evaporation ◽  
Behavior Understanding ◽  
Main Component

AbstractMeasuring biological samples by atom probe tomography (APT) in their natural environment, i.e. aqueous solution, would take this analytical method, which is currently well established for metals, semi-conductive materials and non-metals, to a new level. It would give information about the 3D chemical structure of biological systems, which could enable unprecedented insights into biological systems and processes, such as virus protein interactions. For this future aim, we present as a first essential step the APT analysis of pure water (Milli-Q) which is the main component of biological systems. After Cryo-preparation, nanometric water tips are field evaporated with assistance by short laser pulses. The obtained data sets of several tens of millions of atoms reveal a complex evaporation behavior. Understanding the field evaporation process of water is fundamental for the measurement of more complex biological systems. For the identification of the individual signals in the mass spectrum, DFT calculations were performed to prove the stability of the detected molecules.

scholarly journals Use of Amount-of-Substance Terminology and Equations in Field Desorption Theory

2020 ◽  
Vol 63 (15-18) ◽  
pp. 1502-1508
Author(s):  
Richard G. Forbes
Keyword(s):  
Atom Probe ◽  
Atomic Level ◽  
Comprehensive System ◽  
Rate Theory ◽  
Dimensional System ◽  
Field Desorption ◽  
Field Evaporation ◽  
Dimensionless Quantity ◽  
Amount Of Substance ◽  
Level Constant

AbstractThis note proposes that the theories of field evaporation and field desorption, as used in atom-probe microscopy and related atomic-level contexts, should be consistently formulated in terms of a set of “seven-dimensional (7-D)” formulae and equations that involve the physical quantity “amount of substance”, but make use of an atomic-level constant effectively equal to “one atom” (or, more generally, “one entity”). It is argued that the term “count” should be introduced as an alternative name (more suited to atomic-level contexts) for the quantity “amount of substance”. For field evaporation/desorption theories, relevant definitions and formulae are proposed, and compared with the “six-dimensional” system (based on the dimensionless quantity “number of atoms/entities”) sometimes used in the literature. Advantages of using a 7-D system are noted. It is argued that there is also an increasing need for a comprehensive system of official nomenclature for atomic-level constants and units, for all three of the extensive quantities “mass”, “electric charge” and “amount of substance”. It is also argued that, in the longer term, considerations of the kind being proposed here for field evaporation/desorption theories might usefully be applied more generally in atomic-level rate theory.

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