The electric field distribution in the field ion microscope as a function of specimen shank

Abstract

A new empirical field calibration equation is presented. This relationship is obtained from a detailed numerical study of the field distribution within a real field ion microscope. The equation separates the important shank angle effect from the other geometric influences. Comparison is made of the predicted field with actual values.

Dynamic reconstruction for atom probe tomography

“…A consistent trend is observed whereby both the field and image compression factors decrease as the specimen progressively blunts during the analysis. This trend was expected based upon several previous theoretical studies [17,28,30] and some other preliminary measurements [27]. Importantly,…”

Impact of laser pulsing on the reconstruction in an atom probe tomography

“…Here, as the facet around the (0 0 2) pole gets flatter, one could assume that this results in a relative decrease of the electric field at the apex, thus in an increase of k f with the radius, conversely to what is effectively observed. The experimental trend was, however, expected from the work of Gipson et al [45,46], where a finite-element method and was used to estimate the electric field in the vicinity of a field-ion microscopy specimen in a realistic microscope geometry. They proposed an advanced description of the field factor that accounts not only for the divergence from sphericity, but also for the far-field geometry and parameters specific to the specimen, such as its length, size, radius of curvature or shank angle.…”

“…Hence, both parameters should be inversely proportional to the radius of curvature. The dependence of the field factor with the radius of curvature was introduced by Gipson et al [46]. We propose here that both parameters are somehow linked together, since they both find their origin in the combination of specimen and microscope geometries.…”

Atom probe tomography spatial reconstruction: Status and directions

“…presence of a substrate, distance to an extraction electrode, etc.) [8][9][10][11][12][13]. This intrinsic dichotomy between effects in the near and far field has long been known [14].…”