Related papers: Role of defects in atom probe analysis of sol-gel …
Two decades after its introduction, laser-assisted Atom Probe Tomography (La-APT) has demonstrated a unique potential for the study of the 3D distribution of atomic species in semiconductor materials and devices, and in a growing list of…
We studied the influence of defect states on the laser excitation process in silicon using time-dependent density functional theory. We assumed two types of point defects: interstitial oxygen and silicon vacancies. We found that the…
Atom probe tomography (APT) enables near atomic scale three dimensional elemental mapping through the controlled field evaporation of surface atoms triggered by the combined application of a DC voltage and either voltage or laser pulses. As…
This experimental PhD work deals with the generation and transformation processes of point defects induced by UV laser irradiation on amorphous silicon dioxide (silica). The investigation relies on several spectroscopic techniques used to…
It is shown for the first time, that room temperature Ultrasonic Defect Manipulation (UDM) can significantly reduce the concentration of radiation defects in high resistivity silicon. Secondary Ion Mass Spectroscopy revealed that oxygen-…
Monazite (CePO4) is widely used in U-Th-Pb geochronology due to its reliable age determinations, although isotopic disturbances often require nanoscale investigation to better understand the mechanisms at play. Atom Probe Tomography (APT)…
In the present Ph.D. Thesis we report an experimental investigation on the effects of gamma- and beta-ray irradiation and of subsequent thermal treatment on many types of a-SiO2 materials, differing in the production methods, OH- and…
Atom probe tomography (APT) provides the three-dimensional composition of materials at near-atomic length scales, achieving detection limits in the range of tens of atomic parts-per-million regardless of element type. APT requires the…
The design of catalysts with desired chemical and thermal properties is viewed as a grand challenge for scientists and engineers. For operation at high temperatures, stability against structural transformations is a key requirement.…
Recent advances in scanning transmission electron and scanning tunneling microscopies allow researchers to measure materials structural and electronic properties, such as atomic displacements and charge density modulations, at an Angstrom…
Using a combination of quantum and classical computational approaches, we model the electronic structure in amorphous silicon in order gain understanding of the microscopic atomic configurations responsible for light induced degradation of…
Atom probe tomography (APT) is extensively used to measure the local chemistry of materials. Site-specific preparation via a focused ion beam (FIB) is routinely implemented to fabricate needle-shaped specimens with an end radius in the…
Atom probe tomography (APT) is routinely used for analyzing property-enhancing particles in the nanometer-size range and below, and plays a prominent role in the analysis of solute clusters. However, the question of how well these small…
Here, we evaluate multislice electron ptychography as a tool to carry out depth-resolved atomic resolution characterization of point defects, using silicon carbide as a case study. Through multislice electron scattering simulations and…
The influence of oxygen and carbon impurities on the concentrations of defects in silicon for detector uses, in complex fields of radiation, characteristic to high energy physics experiments, is investigated in the frame of the quantitative…
The accurate determination of atom numbers is an ubiquitous problem in the field of ultracold atoms. For modest atom numbers, absolute calibration techniques are available, however, for large numbers and high densities, the available…
The folding and structure of biomacromolecules depend on the 3D distributions of their constituents, which ultimately controls their functionalities and interactions with other biomacromolecules. Atom probe tomography (APT) with its…
A phenomenological model was developed to explain quantitatively, without free parameters, the production of primary defects in silicon after particle irradiation, the kinetics of their evolution toward equilibrium and their influence on…
Silicon detectors in particle physics experiments at the new accelerators or in space missions for physics goals will be exposed to extreme radiation conditions. The principal obstacles to long-term operation in these environments are the…
Laser enhanced field evaporation of surface atoms in Laser-assisted Atom Probe Tomography (La-APT) can simultaneously excite phtotoluminescence in semiconductor or insulating specimens. An atom probe equipped with appropriate focalization…