On the Field Evaporation Behavior of Dielectric Materials in Three-Dimensional Atom Probe: A Numeric Simulation

2010 ◽  
Vol 17 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Christian Oberdorfer ◽  
Guido Schmitz
Keyword(s):  
Dielectric Properties ◽  
Three Dimensional ◽  
Atom Probe ◽  
Dielectric Materials ◽  
Field Evaporation ◽  
Volume Reconstruction ◽  
Major Improvement ◽  
Numeric Simulation ◽  
Atom Probes ◽  
3D Volume

AbstractAs a major improvement in three-dimensional (3D) atom probe, the range of applicable material classes has recently been broadened by the establishment of laser-assisted atom probes (LA-3DAP). Meanwhile, measurements of materials of low conductivity, such as dielectrics, ceramics, and semiconductors, have widely been demonstrated. However, besides different evaporation probabilities, heterogeneous dielectric properties are expected to give rise to additional artifacts in the 3D volume reconstruction on which the method is based. In this article, these conceivable artifacts are discussed based on a numeric simulation of the field evaporation. Sample tips of layer- or precipitate-type geometry are considered. It is demonstrated that dielectric materials tend to behave similarly to metals of reduced critical evaporation field.

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.

First Data from a Commercial Local Electrode Atom Probe (LEAP)

2004 ◽  
Vol 10 (3) ◽  
pp. 373-383 ◽  
Author(s):  
Thomas F. Kelly ◽  
Tye T. Gribb ◽  
Jesse D. Olson ◽  
Richard L. Martens ◽  
Jeffrey D. Shepard ◽  
...  
Keyword(s):  
Data Collection ◽  
Three Dimensional ◽  
Atom Probe ◽  
Field Of View ◽  
Performance Parameters ◽  
Scientific Instruments ◽  
Materials Analysis ◽  
Collection Rate ◽  
Atom Probes

The first dedicated local electrode atom probes (LEAP [a trademark of Imago Scientific Instruments Corporation]) have been built and tested as commercial prototypes. Several key performance parameters have been markedly improved relative to conventional three-dimensional atom probe (3DAP) designs. The Imago LEAP can operate at a sustained data collection rate of 1 million atoms/minute. This is some 600 times faster than the next fastest atom probe and large images can be collected in less than 1 h that otherwise would take many days. The field of view of the Imago LEAP is about 40 times larger than conventional 3DAPs. This makes it possible to analyze regions that are about 100 nm diameter by 100 nm deep containing on the order of 50 to 100 million atoms with this instrument. Several example applications that illustrate the advantages of the LEAP for materials analysis are presented.

scholarly journals Study on the Field Evaporation in the Laser-assisted Three-dimensional Atom Probe Based on the Thermal Diffusivity

2014 ◽  
Vol 63 (10) ◽  
pp. 809-815 ◽  
Author(s):  
Takahiro ASAKA ◽  
Bunbunoshin TOMIYASU ◽  
Masato MORITA ◽  
Tetsuo TERAKAWA ◽  
Masanori OWARI
Keyword(s):  
Thermal Diffusivity ◽  
Three Dimensional ◽  
Atom Probe ◽  
Field Evaporation

scholarly journals Efficient 3D Volume Reconstruction from a Point Cloud Using a Phase-Field Method

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Darae Jeong ◽  
Yibao Li ◽  
Heon Ju Lee ◽  
Sang Min Lee ◽  
Junxiang Yang ◽  
...  
Keyword(s):  
Image Segmentation ◽  
Numerical Method ◽  
Phase Field ◽  
Point Cloud ◽  
Three Dimensional ◽  
Field Method ◽  
Phase Field Method ◽  
Volume Reconstruction ◽  
Hybrid Numerical Method ◽  
3D Volume

We propose an explicit hybrid numerical method for the efficient 3D volume reconstruction from unorganized point clouds using a phase-field method. The proposed three-dimensional volume reconstruction algorithm is based on the 3D binary image segmentation method. First, we define a narrow band domain embedding the unorganized point cloud and an edge indicating function. Second, we define a good initial phase-field function which speeds up the computation significantly. Third, we use a recently developed explicit hybrid numerical method for solving the three-dimensional image segmentation model to obtain efficient volume reconstruction from point cloud data. In order to demonstrate the practical applicability of the proposed method, we perform various numerical experiments.

Atom probes of the future

1994 ◽  
Vol 52 ◽  
pp. 834-835
Author(s):  
T. F. Kelly ◽  
P. P. Camus ◽  
D. J. Larson ◽  
L. M. Holzman
Keyword(s):  
Three Dimensional ◽  
Atom Probe ◽  
Atomic Scale ◽  
3D Images ◽  
New Era ◽  
Atom Probes ◽  
Position Sensitive ◽  
Third Dimension ◽  
Position Sensitive Detectors ◽  
Very High

Atom probe microscopy, which is based on the first ever atomic-scale imaging technique, field ion microscopy (FIM), has entered a new era in its development. Three-dimensional atom probes (3DAP) are now operating which produce 3D images with atomic scale resolution. It appears that the technology will soon be at hand to make 3DAPs do everything that their predecessor, the conventional atom probe, now does and also reach the third dimension. These microscopes will be simpler, smaller, faster, and much more powerful than the conventional atom probe. Several developments are responsible for this suggestion. 1) Rapid pulsing schemes are being developed which will make it possible to achieve on the order of 106 pulses per second. 2) Highspeed position-sensitive detectors (PSDs) have been designed which can detect several ions in a givenpulse with very high precision. 3) New specimen geometries will soon become possible which will revolutionize the atom probe. Let us consider the ramifications of each of these developments in turn.

A New Approach to the Determination of Concentration Profiles in Atom Probe Tomography

2012 ◽  
Vol 18 (2) ◽  
pp. 359-364 ◽  
Author(s):  
Peter J. Felfer ◽  
Baptiste Gault ◽  
Gang Sha ◽  
Leigh Stephenson ◽  
Simon P. Ringer ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Three Dimensional ◽  
Atom Probe ◽  
Solute Concentration ◽  
Concentration Profiles ◽  
Field Evaporation ◽  
New Approach ◽  
Depth Direction ◽  
Spread Function

AbstractAtom probe tomography (APT) provides three-dimensional analytical imaging of materials with near-atomic resolution using pulsed field evaporation. The processes of field evaporation can cause atoms to be placed at positions in the APT reconstruction that can deviate slightly from their original site in the material. Here, we describe and model one such process—that of preferential retention of solute atoms in multicomponent systems. Based on relative field evaporation probabilities, we calculate the point spread function for the solute atom distribution in the “z,” or in-depth direction, and use this to extract more accurate solute concentration profiles.

Characterisation of Ultrafine Microstructures Using a Position-Sensitive Atom Probe (POSAP)

1988 ◽  
Vol 132 ◽  
Author(s):  
Alfred Cerezo ◽  
Chris R. M. Grovenor ◽  
Mark G. Hetherington ◽  
Barbara A. Shollock ◽  
George D. W. Smith
Keyword(s):  
Solid Angle ◽  
Three Dimensional ◽  
Atom Probe ◽  
Field Evaporation ◽  
Sensitive Detector ◽  
Substantial Fraction ◽  
New Instrument ◽  
New Development ◽  
Position Sensitive ◽  
Permanent Magnet Materials

ABSTRACTA new development in the experimental techniques of atom probe microanalysis is described, which involves the use of a position sensitive detector system. This detector subtends a large solid angle (∼20°) at the specimen, and therefore permits the collection of ions from a substantial fraction of the whole surface area of the emitter. Progressive pulsed field evaporation leads to the construction of a three-dimensional map of the atomic chemistry of the specimen. The new instrument is ideally suited to the investigation of complex, ultrafine microstructures. Applications to the study of age-hardened aluminium alloys and Alnico permanent magnet materials are described.

Progress in the Atomic-Scale Analysis of Materials with the Three-Dimensional Atom Probe

MRS Bulletin ◽  
2001 ◽  
Vol 26 (2) ◽  
pp. 102-107 ◽  
Author(s):  
A. Cerezo ◽  
D. J. Larson ◽  
G. D. W. Smith
Keyword(s):  
Three Dimensional ◽  
Atom Probe ◽  
Atomic Scale ◽  
Single Atoms ◽  
Flight Mass Spectrometry ◽  
Atom Probes ◽  
Distribution Of Elements ◽  
The Subject ◽  
The Individual ◽  
Field Ion Microscope

Exactly 50 years ago, E.W. Müller became the first person to observe single atoms, with the aid of the field-ion microscope (FIM). In 1967, with John Panitz and S. Brooks McLane, Müller's invention of the atom probe meant that, in his words, “We can now really deal much more intimately with the individual atoms which we encounter, since we know their names.” By combining position-sensitive detection with the time-of-flight mass spectrometry of single atoms in the atom probe, Cerezo and co-workers in the late 1980s built an instrument capable of reconstructing the three-dimensional (3D) atomic distribution of elements present in a material. The instruments that are capable of microanalysis at this level, called generically 3D atom probes (3DAPs), were the subject of two articles published in MRS Bulletin in 1994. In this article, we review some of the progress in the field since that time, in particular, the expansion of the range of materials problems that can be addressed by this powerful technique.

Interpreting Atom Probe Data from Oxide–Metal Interfaces

2018 ◽  
Vol 24 (4) ◽  
pp. 342-349 ◽  
Author(s):  
Ingrid McCarroll ◽  
Barbara Scherrer ◽  
Peter Felfer ◽  
Michael P. Moody ◽  
Julie M. Cairney
Keyword(s):  
Atom Probe Tomography ◽  
Three Dimensional ◽  
Atom Probe ◽  
Atomic Scale ◽  
Field Evaporation ◽  
Correlative Microscopy ◽  
Reconstruction Process ◽  
Simulation Techniques ◽  
Field Simulation ◽  
Metal Interfaces

AbstractUnderstanding oxide–metal interfaces is crucial to the advancement of materials and components for many industries, most notably for semiconductor devices and power generation. Atom probe tomography provides three-dimensional, atomic scale information about chemical composition, making it an excellent technique for interface analysis. However, difficulties arise when analyzing interfacial regions due to trajectory aberrations, such as local magnification, and reconstruction artifacts. Correlative microscopy and field simulation techniques have revealed that nonuniform evolution of the tip geometry, caused by heterogeneous field evaporation, is partly responsible for these artifacts. Here we attempt to understand these trajectory artifacts through a study of the local evaporation field conditions. With a better understanding of the local evaporation field, it may be possible to account for some of the local magnification effects during the reconstruction process, eliminating these artifacts before data analysis.

Modeling Image Distortions in 3DAP

2004 ◽  
Vol 10 (3) ◽  
pp. 384-390 ◽  
Author(s):  
F. Vurpillot ◽  
A. Cerezo ◽  
D. Blavette ◽  
D.J. Larson
Keyword(s):  
Grain Boundary ◽  
Three Dimensional ◽  
Atom Probe ◽  
Atomic Scale ◽  
Field Evaporation ◽  
Mesoscopic Scale ◽  
Two Phase ◽  
The Matrix ◽  
Precipitated Phases ◽  
Good Agreement

A numerical model has been developed to simulate images obtained from the three-dimensional atom probe. This model was used to simulate the artefacts commonly observed in two-phase materials. This model takes into account the dynamic evolution of the atomic-scale shape of the specimen during field evaporation. This article reviews the model and its applications to some specific cases. Local magnification effects were studied as a function of the size, the shape, and the orientation of precipitated phases embedded in the matrix. Small precipitates produce large aberrations in good agreement with experiments. The magnification from such precipitates, as measured from the simulation, is only found to match the theoretical value for mesoscopic scale precipitates (size similar to the specimen size). Orientation effects are also observed in excellent agreement with experiments. The measured thickness of a grain-boundary-segregated film in the simulation is found to decrease with the angle between the normal to the grain boundary and the tip axis. Depth scaling artefacts caused by variation in the evaporation field of atoms in multilayer structures were successfully simulated and again showed good agreement with effects observed experimentally.

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