Computer-controlled time-of-flight atom-probe field-ion microscope for the study of defects in metals

A computer-controlled atom probe time-of-flight mass spectrometer-field ion microscope system has been developed which permits chemical microanalysis of metals and alloys with approximately 1 nm spatial resolution, good quantitative accuracy and excellent sensitivity for the detection of trace elements. The mass resolution is sufficient to separate adjacent isotopes of the transition elements, and the detection efficiency for single atoms is approximately 90 %. Operation is carried out under ultra-high vacuum conditions to minimize background noise levels. Detection of local concentrations of trace elements and impurities of the order of 0.1 at. % is routinely obtained with this instrument. An additional analytical facility, termed an imaging field desorption atom probe, (i.f.d.a.p.) has also recently been constructed. This produces a picture of the spatial distribution of a selected chemical element over the whole of the imaged region of the field-ion specimen; the information obtained is essentially complementary to that from the conventional time-of-flight atom probe.

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Fabrication and characterization - by High Resolution Electron Microscopy and atom probe microanalysis - of Co-based metallic multilayer films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010017699x ◽

1990 ◽

Vol 48 (4) ◽

pp. 772-773

Author(s):

Amanda K. Petford-Long ◽

A. Cerezo ◽

M.G. Hetherington

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

High Resolution Electron Microscopy ◽

Atom Probe ◽

Multilayer Films ◽

Interface Roughness ◽

Probe Field ◽

Resolution Electron ◽

Potential Applications ◽

Field Ion Microscope

The fabrication of multilayer films (MLF) with layer thicknesses down to one monolayer has led to the development of materials with unique properties not found in bulk materials. The properties of interest depend critically on the structure and composition of the films, with the interfacial regions between the layers being of particular importance. There are a number of magnetic MLF systems based on Co, several of which have potential applications as perpendicular magnetic (e.g Co/Cr) or magneto-optic (e.g. Co/Pt) recording media. Of particular concern are the effects of parameters such as crystallographic texture and interface roughness, which are determined by the fabrication conditions, on magnetic properties and structure.In this study we have fabricated Co-based MLF by UHV thermal evaporation in the prechamber of an atom probe field-ion microscope (AP). The multilayers were deposited simultaneously onto cobalt field-ion specimens (for AP and position-sensitive atom probe (POSAP) microanalysis without exposure to atmosphere) and onto the flat (001) surface of oxidised silicon wafers (for subsequent study in cross-section using high-resolution electron microscopy (HREM) in a JEOL 4000EX. Deposi-tion was from W filaments loaded with material in the form of wire (Co, Fe, Ni, Pt and Au) or flakes (Cr). The base pressure in the chamber was around 8×10−8 torr during deposition with a typical deposition rate of 0.05 - 0.2nm/s.

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Field emission and atom probe field ion microscope studies of palladium-silicide-coated silicon emitters

Journal of Vacuum Science & Technology B Microelectronics Processing and Phenomena ◽

10.1116/1.587923 ◽

1995 ◽

Vol 13 (2) ◽

pp. 603 ◽

Cited By ~ 6

Author(s):

R. A. King

Keyword(s):

Field Emission ◽

Atom Probe ◽

Probe Field ◽

Palladium Silicide ◽

Field Ion Microscope

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