A cross-correlative precession electron diffraction - atom probe tomography investigation of Cr segregation in a Fe(Cr) nanocrystalline alloy was undertaken. Solute segregation was found to be dependent on grain boundary type. The results of which were compared to a hybrid Molecular Dynamics and Monte Carlo simulation that predicted the segregation for special character, low angle, and high angle grain boundaries, as well as the angle of inclination of the grain boundary.
View Article and Find Full Text PDFThe effects of laser wavelength (355 nm and 532 nm) and laser pulse energy on the quantitative analysis of LiFePO₄ by atom probe tomography are considered. A systematic investigation of ultraviolet (UV, 355 nm) and green (532 nm) laser assisted field evaporation has revealed distinctly different behaviors. With the use of a UV laser, the major issue was identified as the preferential loss of oxygen (up to 10 at%) while other elements (Li, Fe and P) were observed to be close to nominal ratios.
View Article and Find Full Text PDFThe 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.
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