A refined model of the metal surface and its interaction with gases in the field ion microscope

1968 ◽  
Vol 10 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Zlatko Knor ◽  
Erwin W. Müller
1998 ◽  
Vol 4 (S2) ◽  
pp. 74-75 ◽  
Author(s):  
J. A. Panitz

The Atom-Probe Field Ion Microscope was introduced in 1967 at the 14th Field Emission Symposium in Gaithersburg, Maryland. The Atom-Probe was, and remains, the only instrument capable of determining “the nature of one single atom seen on a metal surface and selected from neighboring atoms at the discretion of the observer”. The development of the Atom-Probe is a story that highlights Erwin Muller's strong and sometimes volatile personality. It is a story of an instrument that one NSF proposal reviewer called “impossible” because “single atoms could not be detected”. It is also the story of the Field Emission Laboratory at Penn State in the late 1960s and the contributions of two superb technicians, Gerald Fowler and Brooks McLane, and two graduate students, Douglas Barofsky and John Panitz. The anecdotes from this time are colorful and reflect Erwin's pedigree as Gustav Hertz's student in the Berlin of the 1930s.


1985 ◽  
Vol 48 ◽  
Author(s):  
John D. Wrigley ◽  
Gert Ehrlich

ABSTRACTWith the field-ion microscope one not only can locate individual atoms at a surface, but under some circumstances also can discriminate between chemically different species. These capabilities are illustrated in an examination of the strength of binding in silicon-metal surface clusters and in a detailed analysis of their mobility.


Author(s):  
O. T. Inal ◽  
L. E. Murr

When sharp metal filaments of W, Fe, Nb or Ta are observed in the field-ion microscope (FIM), their appearance is differentiated primarily by variations in regional brightness. This regional brightness, particularly prominent at liquid nitrogen temperature has been attributed in the main to chemical specificity which manifests itself in a paricular array of surface-atom electron-orbital configurations.Recently, anomalous image brightness and streaks in both fcc and bee materials observed in the FIM have been shown to be the result of surface asperities and related topographic features which arise by the unsystematic etching of the emission-tip end forms.


Author(s):  
L.E. Murr ◽  
V. Annamalai

Georgius Agricola in 1556 in his classical book, “De Re Metallica”, mentioned a strange water drawn from a mine shaft near Schmölnitz in Hungary that eroded iron and turned it into copper. This precipitation (or cementation) of copper on iron was employed as a commercial technique for producing copper at the Rio Tinto Mines in Spain in the 16th Century, and it continues today to account for as much as 15 percent of the copper produced by several U.S. copper companies.In addition to the Cu/Fe system, many other similar heterogeneous, electrochemical reactions can occur where ions from solution are reduced to metal on a more electropositive metal surface. In the case of copper precipitation from solution, aluminum is also an interesting system because of economic, environmental (ecological) and energy considerations. In studies of copper cementation on aluminum as an alternative to the historical Cu/Fe system, it was noticed that the two systems (Cu/Fe and Cu/Al) were kinetically very different, and that this difference was due in large part to differences in the structure of the residual, cement-copper deposit.


Author(s):  
Gert Ehrlich

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.


Author(s):  
J. J. Hren ◽  
S. D. Walck

The field ion microscope (FIM) has had the ability to routinely image the surface atoms of metals since Mueller perfected it in 1956. Since 1967, the TOF Atom Probe has had single atom sensitivity in conjunction with the FIM. “Why then hasn't the FIM enjoyed the success of the electron microscope?” The answer is closely related to the evolution of FIM/Atom Probe techniques and the available technology. This paper will review this evolution from Mueller's early discoveries, to the development of a viable commercial instrument. It will touch upon some important contributions of individuals and groups, but will not attempt to be all inclusive. Variations in instrumentation that define the class of problems for which the FIM/AP is uniquely suited and those for which it is not will be described. The influence of high electric fields inherent to the technique on the specimens studied will also be discussed. The specimen geometry as it relates to preparation, statistical sampling and compatibility with the TEM will be examined.


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