Complementary use of TEM and APT for the investigation of steels nanostructured by severe plastic deformation

The properties of bulk nanostructured materials are often controlled by atomic scale features like segregation along defects or composition gradients. Here we discuss about the complimentary use of TEM and APT to obtain a full description of nanostructures. The advantages and limitations of both techniques are highlighted on the basis of experimental data collected in severely deformed steels with a special emphasis on carbon spatial distribution

Effects of incidence angles of ions on the mass resolution of an energy compensated 3D atom probe

Abstract We have used a first-order reflectron lens in an optical tomographic atom probe in order to improve the mass resolution. Calculations have been performed to determine the effect of second-order errors in ion energy and incidence angle on the performance of the lens. By applying a correction procedure based on the results of these calculations, we have been able to improve experimental mass resolution by 30%.

A Photonic Atom Probe coupling 3D Atomic Scale Analysis with in situ Photoluminescence Spectroscopy

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 and collection optics has been coupled with an in-situ micro-Photoluminescence ({\mu}PL) bench that can be operated during APT analysis. The Photonic Atom Probe instrument we have developped operates at frequencies up to 500 kHz and is controlled by 150 fs laser pulses tunable in energy in a large spectral range (spanning from deep UV to near IR). Micro-PL spectroscopy is performed using a 320 mm focal length spectrometer equipped with a CCD camera for time-integrated and with a streak camera for time-resolved acquisitions. An exemple of application of this instrument on a multi-quantum well oxide heterostructure sample illustrates the potential of this new generation of tomographic atom probe.Comment: 22 pages, 4 figures. The following article has been accepted by the Review of Scientific Instruments. After it is published, it will be found at https://publishing.aip.org/resources/librarians/products/journals

Contribution of 3D atom probe to the understanding of plane-by-plane AP analyses data: application to the study of ordering in Cu3Au

International audienc

Contribution of 3D atom probe to the understanding of plane-by-plane AP analyses data: application to the study of ordering in Cu3Au

International audienc

Modeling artifacts in the analysis of test semiconductor structures in atom probe tomography

International audienceIn this paper, the investigation of boron delta layers by atom probe tomography is used to demonstrate that a sub nanometer resolution (0.9 nm full-width at half-maximum, FWHM) can be achieved. This resolution is surprisingly lower than the intrinsic resolution observed in silicon (0.2 nm). Reconstruction artifacts are suggested. In this paper, the extent of reconstruction artifacts is evaluated using a model that reproduces the field evaporation of the sample and the image reconstruction. It is shown that reconstruction artifacts can only account for half of the resolution degradation, suggesting an actual physical depth of delta doped B layer of about 0.5 nm

Étude des microstructures à l'échelle atomique par sonde atomique 3D

International audienc

Modeling artifacts in the analysis of test semiconductor structures in atom probe tomography

International audienceIn this paper, the investigation of boron delta layers by atom probe tomography is used to demonstrate that a sub nanometer resolution (0.9 nm full-width at half-maximum, FWHM) can be achieved. This resolution is surprisingly lower than the intrinsic resolution observed in silicon (0.2 nm). Reconstruction artifacts are suggested. In this paper, the extent of reconstruction artifacts is evaluated using a model that reproduces the field evaporation of the sample and the image reconstruction. It is shown that reconstruction artifacts can only account for half of the resolution degradation, suggesting an actual physical depth of delta doped B layer of about 0.5 nm

Étude des microstructures à l'échelle atomique par sonde atomique 3D

International audienc

Bright and ultrafast electron point source made of LaB6 nanotip

International audienceLaB6 has been traditionally used as a thermionic electron source for electron microscopes, but has been hardly set to practical use as cold field emitter (CFE) [1-2]. The chemical inertness, the high conductivity and the dense structure make LaB6 a good candidate as ultrafast electron source. In the present work, we study the emission properties of LaB6 nano-tip fabricated by focused ion beam milling, under static electric field (static emission) and under femtosecond laser illumination (ultrafast emission), using a 2.25μm laser at 13 MHz