LEAP

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The LEAP 4000X Si at NUCAPT

The LEAP 4000X Si, manufactured by CAMECA, Madison, Wisconsin, is a local electrode atom-probe (LEAP) tomograph with ultrafast detection of up to 360 million ions per hour. Ions are evaporated from a sample’s surface either by voltage or ultraviolet (UV) laser pulses, which allows for the analysis of a broad spectrum of materials: metals, semiconductors, ceramics, biominerals, organic and biological samples, albeit with different degrees of success. A computer reconstructs a three-dimensional image of a sample with both the chemical identities and positions of individual atoms, with a depth resolution equal to the interplanar spacing, which can be as small as 0.1 nm: the lateral resolution in an atomic plane is between 0.3 to 0.5 nm. The microelectrode in the LEAP tomograph allows the analysis of microtips, prepared by FIB (ion-milling and/or the lift-out technique to target specific features), or wire microtips prepared by conventional electropolishing. Additionally, digital field-ion microscopy can be performed with this instrument..

NUCAPT's LEAP
Schematic of LEAP

Imago Scientific Instruments has developed their Local-Electrode Atom-Probe (LEAP) tomograph. Like a traditional Atom-Probe Tomograph (APT), the LEAP tomograph achieves true 3-D atomic-scale analysis by using a high electric field to remove individual atoms from material surfaces and a position-sensitive detector to record information that reveals the atom's position and identity. However, the incorporation of a local electrode eliminates or mitigates many of the performance limitations of traditional APTs. The Imago LEAP tomograph analyzes significantly larger volumes (typically 50 x 50 x 100nm) in much less time (minutes). Further, the LEAP tomograph is compatible with a variety of specimen geometries, including specimens made with TEM-like techniques.

The NUCAPT LEAP tomograph has collected over 150,075,286,683 "good hits" since December 7, 20041.

1This number is calculated in live-time. However, your browser might be retrieving this page from a cache. You might need to bypass your cache or click here to purge the server cache. Many of these "good hits" are single ions, but some are multi-ion hits. (Ions for discarded or interrupted runs aren't counted, nor are "bad hits.")

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