Atom Probe Research Articles

Towards Improved Measurement of Chemical Composition and Isotope Ratios of Rare-earth Phosphates in Atom Probe Tomography

Towards Improved Measurement of Chemical Composition and Isotope Ratios of Rare-earth Phosphates in Atom Probe Tomography

Multi-Dimensional Characterization of Nanostructures in Titanium Alloys using 2D Aberration-Corrected STEM and 3D Atom Probe Tomography

Multi-Dimensional Characterization of Nanostructures in Titanium Alloys using 2D Aberration-Corrected STEM and 3D Atom Probe Tomography

State-of-the-Art and Future Directions of fs-Laser Assisted Specimen Preparation Techniques for Atom Probe Tomography Measurements

State-of-the-Art and Future Directions of fs-Laser Assisted Specimen Preparation Techniques for Atom Probe Tomography Measurements

High-Pressure Resin Embedment of Mesoporous Silica Supported Nanoparticles for High-Quality Atom Probe Tomography Analysis

High-Pressure Resin Embedment of Mesoporous Silica Supported Nanoparticles for High-Quality Atom Probe Tomography Analysis

Resolving Hydrogen Trapping Sites in Steels at Ultra-High Resolution Using Cryogenic Atom Probe Tomography

Resolving Hydrogen Trapping Sites in Steels at Ultra-High Resolution Using Cryogenic Atom Probe Tomography

A Machine Learning based Workflow to Quantify Atom Probe Tomography Data

A Machine Learning based Workflow to Quantify Atom Probe Tomography Data

Considerations for using Calibration Curves to Infer Oxide Stoichiometry from Atom Probe Tomography Data

Considerations for using Calibration Curves to Infer Oxide Stoichiometry from Atom Probe Tomography Data

Evaluation of Stoichiometric Accuracy with Deep-Ultraviolet Laser-Assisted Atom Probe Tomography of Hydroxyapatite

Evaluation of Stoichiometric Accuracy with Deep-Ultraviolet Laser-Assisted Atom Probe Tomography of Hydroxyapatite

Coupled Transmission Electron Microscopy and Atom Probe Tomography Reveals an Interesting Pathway to Nanolamellar Microstructures in High Entropy Alloys

Coupled Transmission Electron Microscopy and Atom Probe Tomography Reveals an Interesting Pathway to Nanolamellar Microstructures in High Entropy Alloys

Unraveling the potential of Cu addition and cluster hardening in Al-Mg-Si alloys

With the aim of further exploiting the trade-off between formability and strength in Al alloys, this study addresses the influence of Cu in Al-Mg-Si alloys that achieve simultaneously high strength and high ductility via cluster hardening. The study carefully examines the mechanical properties and strain hardening behavior of various Mg/Si ratios with and without Cu and compares the effects of pre-aging and atypical long-term low-temperature aging treatments at 100°C to conventional heat treatments. Interestingly, in all cases adding Cu improved ductility. In the extremal case cluster hardening plus the addition of Cu quadruples elongation, while keeping yield strength similar to the classical T6 state. The results of the study are discussed with a focus on the dense distribution of clusters and partial hardening phases based on atom probe tomography data. Most importantly, the cluster-hardened alloys exhibit pronounced strain-hardening properties, which we evaluate using a Kocks-Mecking approach in combination with a microstructural analysis in the pre-aging and long-term aging condition. The key finding of the study involves the role of Cu in refining clusters/precipitates, where it causes a substantial increase in number density and volume fraction. This refinement, in combination with strain-induced clustering, contributes significantly to improving the alloys’ overall mechanical performance and underlines the central role of Cu in tailoring microstructural features, especially in alloys primarily strengthened by clusters.

Spatial Ranging and Volume Segmentation of Atom Probe Tomography Data

Spatial Ranging and Volume Segmentation of Atom Probe Tomography Data

Ranging Atom Probe Spectra to Reduce Measurement Bias

Ranging Atom Probe Spectra to Reduce Measurement Bias

How Can 4D-STEM Inform Atom Probe Experiments? Relating Structure and Composition of Multiferroic Oxides at the Atomic Scale

How Can 4D-STEM Inform Atom Probe Experiments? Relating Structure and Composition of Multiferroic Oxides at the Atomic Scale

A High Kinetic Energy Atom Probe Design to Improve Instrument Performances in Voltage Pulse Mode

A High Kinetic Energy Atom Probe Design to Improve Instrument Performances in Voltage Pulse Mode

Magnetic imaging of individual magnetosome chains in magnetotactic bacteria

While significant advances have been made in exploring and uncovering the promising potential of biomagnetic materials, persistent challenges remain on various fronts, notably in the characterization of individual elements. This study makes use of advanced modes of Magnetic Force Microscopy (MFM) and tailored MFM probes to characterize individual magnetotactic bacteria in different environments. The characterization of these elements posed a significant challenge, as the magnetosomes, besides presenting low magnetic signal, are embedded in bacteria of much larger size. To overcome this, customed Atomic Force Microscopy probes are developed through various strategies, enhancing sensitivity in different environments, including liquids. Furthermore, employing MFM imaging under an in-situ magnetic field provides an opportunity to gather quantitative data regarding the critical fields of these individual chains of nanoparticles. This approach marks a substantial advancement in the field of MFM for biological applications, enabling the detection of magnetosomes under different conditions.

Clustering behaviour of pre-aged Al-Mg-Si alloy during subsequent natural ageing and paint baking

The clustering behaviour of a pre-aged Al-Mg-Si alloy during natural ageing (NA) and paint baking (PB) was systematically investigated by hardness measurements and atom probe tomography (APT). The results show that pre-ageing (PA) can effectively retard the negative effect of NA and enhance the paint-baking response even after long-term NA (up to one year). The pre-aged alloy shows a good resistance against clustering within a short NA period of one week, and the capability is enhanced with increasing pre-ageing time. However, the clustering becomes significant after prolonged NA, especially for one year. The increasing number density of clusters containing 10–30 solute atoms contributes most to the hardness increase after prolonged NA. The mechanism about two synergistic processes of ‘vacancy trap’ and ‘vacancy escape’ is introduced to explain the phenomenon. The alloy with a prior PA above 2 h exhibits a good PB response even after one-year NA. Such performance is attributed to large-size precipitates (GP zones or pre-β″ precipitates) formed during PA, which can serve as nuclei for β″ due to a similar composition. Moreover, a strength model has been established to predict the different strengthening effect and evaluate contributions from clusters, GP zones and pre-β″/β″ precipitates during multi-stage ageing in the Al-Mg-Si alloy.

Characterization of tooth with amelogenesis imperfecta (AI) by atom probe tomography

Characterization of tooth with amelogenesis imperfecta (AI) by atom probe tomography

Atomic-level quantum well degradation of GaN-based laser diodes investigated by atom probe tomography

Gallium nitride (GaN)- based lasers are extensively employed in display, lighting, and communication applications due to their visible laser emission. Despite notable advancements in their performance and reliability, sustained device functionality over extended periods remains a challenge. Among the diverse mechanisms contributing to degradation, the deterioration of quantum wells poses a persistent obstacle. In this study, we investigated the atomic-level degradation of quantum wells within GaN-based laser diodes utilizing atom probe microscopy. Our analysis revealed a substantial increase in indium fluctuation, accompanied by the formation of indium protrusions at the quantum well interfaces, which provides a credible explanation for the observed increase in FWHM (full width at half maximum) of the spontaneous spectra of lasers following prolonged operation. Additionally, magnesium analysis yielded no evidence of diffusion into the quantum well region. Combined with prior studies, we attribute the degradation of quantum wells primarily to the formation of indium-related non-radiative recombination centers.

Elemental distribution and site occupancy in a Co-Ni-Al-Ti-Ta-W superalloy

γ'-precipitate strengthened cobalt-based superalloys show promise for higher temperature-capability over nickel-based superalloys due to higher melting temperatures. This study investigates a multicomponent CoNi-based superalloy with composition of 54Co-30Ni-9Al-1Ta-4Ti-2-W (at.%) in terms of elemental partitioning and site occupancy. Atom probe tomography (APT) reveals preferential partitioning of Ni, Al, Ti, Ta and W to the γ'-precipitate and Co to the γ-matrix. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy dispersive spectrometer (EDS) along the [001] zone axis of γ'-precipitate with L12 structure indicate that Co, Ni substitute at A-sites, whereas Al, Ti, Ta, W prefer the B-sites. Density functional theory (DFT) calculations further confirm the results of partitioning behaviors and site preferences. Clarifying elemental partitioning and site occupancy provides valuable insights into alloy design principles for advanced CoNi-based superalloys.

Suppressing Lithium Migration in a Carbon Fiber Negative Electrode During Atom Probe Tomography Analysis.

Carbon fibers can play dual roles, carrying mechanical load and hosting lithium (Li) simultaneously in multifunctional devices called structural batteries. It is essential to gain a detailed understanding on the interaction between Li and carbon fibers on the nanoscale. Atom probe tomography (APT) can potentially reveal individual Li and C atoms. However, lithiated carbon fibers experience massive Li migration once exposed to the electric field in the APT instrument. We show that a few nanometers of a chromium (Cr) coating on APT specimens can shield the electric field and suppress the massive Li migration. The related effects of the Cr coating, such as introduction of oxygen, enhanced mass resolving power of the mass spectrum, and increased portion of single hits, are also discussed.