The atom probe is an atomic-resolution microscope used in materials science that was invented in 1967 by Erwin Müller. It has been suggested that microscopy be merged into this article or section. ... The Materials Science Tetrahedron, which often also includes Characterization at the center Materials science is the multidisciplinary field relating the performance and function of matter in any and all applications to its micro, nano, and atomic-structure, and vice versa. ... 1967 (MCMLXVII) was a common year starting on Sunday of the Gregorian calendar (the link is to a full 1967 calendar). ... Erwin Wilhelm Müller (June 13, 1911 – May 17, 1977) was a German-born physicist who invented the field emission microscope, the field ion microscope, and the atom probe. ...

Müller's atom probe made one-dimensional compositional maps by combining time-of-flight spectroscopy and field ion microscopy (FIM). The instrument now allows the three-dimensional reconstruction of up-to hundreds-of-millions of atoms from a sharp tip (corresponding to specimen volumes of 10,000-1,000,000 nm³). The Time of flight method of measuring particle mass is done as follows. ... Mass spectrometry is an analytical technique to measure the mass-to-charge ratio (m/q) of ions. ... Field ion microscopy (FIM) is an analytical technique used in materials science. ... Properties In chemistry and physics, an atom (Greek άτομον meaning indivisible) is the smallest possible particle of a chemical element that retains its chemical properties. ... A nanometre (American spelling: nanometer) is 1. ...

As in FIM, a sharp tip is made, placed in ultra high vacuum at cryogenic temperature (typically 20-100 K). Individual atoms at the surface of the tip are ionized, either by a positive pulsed voltage or a laser. These ions are repelled from the tip electrostatically. A fast timing circuit is used to measure the time taken between the pulse and the impact of the ion on a detector, thus allowing the mass-to-charge ratio of the ion to be calculated and, therefore, the element (or elements) of the ion. From the collection of many of these ions, a chemical profile of the sample can be made with relative position accuracy of less than one atomic spacing. Ultra high vacuum (UHV) is the regime of characterised by pressures lower than about 10-7 Pascal or 100 nanopascals (~10-9 torr). ...

Atom-Probe Tomography (APT) uses a position-sensitive detector to deduce the lateral location of atoms. It was invented in 1988 by Alfred Cerezo, Terence Godfrey, and George D. W. Smith. 1988 (MCMLXXXVIII) was a leap year starting on Friday of the Gregorian calendar. ... Professor George D. W. Smith (1943, in Aldershot – ...) is a materials scientist who, with Alfred Cerezo and Terence Godfrey, invented the Atom-Probe Tomograph in 1988. ...

External links

• Northwestern University Center for Atom-Probe Tomography
• Metallic Nanostructure group of the National Institute for Materials Science (Japan)
• Imago Scientific Instruments [1]