Atom Probe Tomography
Atom Probe Tomography - Related Videos
09:51
Atom Probe Tomography Studies on the Cu(In,Ga)Se2 Grain Boundaries
0 Views •
Cited by 29 •
2013
In this work, we describe the use of the atom-probe tomography technique for studying the grain boundaries of the absorber layer in a CIGS solar cell. A novel approach to prepare the atom probe tips containing the desired grain boundary with a known structure is also presented here.
08:14
Atom Probe Tomography Analysis of Exsolved Mineral Phases
0 Views •
Cited by 4 •
2019
Analysis of the morphology, composition, and spacing of exsolution lamellae can provide essential information to understand geological processes related to volcanism and metamorphism. We present a novel application of APT for the characterization of such lamellae and compare this approach to the conventional use of electron microscopy and FIB-based nanotomography.
09:52
Probing The Structure And Dynamics Of Nucleosomes Using Atomic Force Microscopy Imaging
0 Views •
Cited by 26 •
2019
Here, we present a protocol to characterize nucleosome particles at the single-molecule level using static and time-lapse atomic force microscopy (AFM) imaging techniques. The surface functionalization method described allows for the capture of the structure and dynamics of nucleosomes in high-resolution at the nanoscale.
01:52
Atomic Mass
0 Views •
2020
Atoms — and the protons, neutrons, and electrons that compose them — are extremely small. For example, a carbon atom weighs less than 2 × 10−23 g. When describing the properties of tiny objects such as atoms, we use appropriately small units of measure, such as the atomic mass unit (amu). The amu was originally defined based on hydrogen, the lightest element, then later in terms of oxygen. Since 1961, it has been defined with regard to the most abundant isotope of carbon, atoms of which are...
02:44
Atomic Orbitals
0 Views •
2020
An atomic orbital represents the three-dimensional regions in an atom where an electron has the highest probability to reside. The radial distribution function indicates the total probability of finding an electron within the thin shell at a distance r from the nucleus. The atomic orbitals have distinct shapes which are determined by l, the angular momentum quantum number. The orbitals are often drawn with a boundary surface, enclosing densest regions of the cloud. The angular momentum...
FAQs
A high voltage creates the field needed to remove surface atoms from the needle-shaped specimen as ions. Laser or voltage pulses control when this field evaporation occurs, while time-of-flight mass spectrometry distinguishes the chemical identity of the ions from their detection timing. Combining identity with detection sequence allows the measured atoms to be assigned within the reconstructed nanoscale structure.
The detection sequence preserves information about how atoms were removed from the specimen surface over time. Atom Probe Tomography uses that sequence, together with the known specimen geometry and ion identities, to reconstruct three-dimensional chemical distributions. This makes it possible to examine where solutes, segregated regions, clusters, precipitates, and interfaces occur rather than only measuring an averaged composition.
Both laser and voltage pulses provide controlled conditions for field-evaporating atoms from the specimen surface. The selected pulse approach determines how ions are generated for subsequent time-of-flight measurement, while the high-voltage environment maintains the field required for evaporation. This pulse-controlled process produces the ordered ion detections needed for chemical identification and three-dimensional reconstruction.
The technique can resolve chemically meaningful features such as interfaces, precipitates, segregation, clustering, and local solute distributions. These features often represent differences in how elements are arranged within a material, rather than simply differences in bulk composition. Their three-dimensional characterization helps engineers connect nanoscale chemical organization with microstructural evolution and material behavior.
The workflow begins by preparing a sharp needle-shaped specimen and placing it under high voltage. Laser or voltage pulses then field-evaporate surface atoms as ions. Time-of-flight mass spectrometry records and identifies the ions, after which the detection sequence is used to reconstruct the specimen’s three-dimensional chemical arrangement. The resulting dataset can then be interpreted in its engineering context.
Engineers use Atom Probe Tomography when processing may change the nanoscale distribution of elements within a material. Measurements of segregation, clustering, precipitates, interfaces, and solute locations provide evidence of how microstructures develop. Relating these chemical changes to processing conditions helps researchers evaluate why a material gains or loses desired performance and supports optimization of advanced alloys and related materials.
The overview identifies metals, semiconductors, and advanced alloys as important engineering material classes for this analysis. Across these systems, the method can examine how elements are distributed around interfaces, precipitates, clusters, or other chemically distinct regions. This broad applicability makes it useful for comparing nanoscale composition with the microstructural requirements of different high-performance materials.
Three-dimensional chemical maps show how solutes and distinct nanoscale features are arranged within an engineering material. Researchers can relate those arrangements to microstructural evolution, mechanical performance, and failure behavior. For example, identifying the chemistry of interfaces, precipitates, segregation, or clusters provides material-specific evidence that can guide the design and optimization of high-performance alloys and other engineered systems.