Field-Ion Microscopy of BCC Metals: A Study of Image Differences and Topographical Variations

1973 ◽  
Vol 31 ◽  
pp. 114-115
Author(s):  
O. T. Inal ◽  
L. E. Murr
Keyword(s):  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Surface Atom ◽  
Image Brightness ◽  
Field Ion Microscopy ◽  
Topographic Features ◽  
Bcc Metals ◽  
Electron Orbital ◽  
Ion Microscopy ◽  
Field Ion Microscope

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.

Field ion microscopy

1988 ◽  
Vol 46 ◽  
pp. 434-435
Author(s):  
Gert Ehrlich
Keyword(s):  
Low Temperature ◽  
Sample Surface ◽  
Low Pressure ◽  
Radius Of Curvature ◽  
Field Ion Microscopy ◽  
Phosphor Screen ◽  
Ion Microscopy ◽  
Field Ion Microscope

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.

The annealing of radiation damage in tungsten investigated by field-ion microscopy

1969 ◽  
Vol 312 (1508) ◽  
pp. 51-63 ◽  
Keyword(s):  
Stage Iii ◽  
Simultaneous Increase ◽  
Field Evaporation ◽  
Field Ion Microscopy ◽  
Interstitial Defect ◽  
Interstitial Defects ◽  
Evaporation Technique ◽  
Ion Microscopy ◽  
Small Clusters ◽  
Field Ion Microscope

Annealed tungsten wire has been reactor-irradiated to a dose of 10 17 n. v. t. ( > 1 MeV), and specimens for field-ion microscopy prepared from the wire. Vacancies could be identified in certain regions of the field-ion microscope image, and the size and shape of small clusters of vacancies could be found by careful field-evaporation. Using the field evaporation technique the clustering of vacancies has been followed in specimens that were unirradiated, irradiated, and given certain post-irradiation heat treatments. The only interstitial defects seen arose from impurities. Specimens examined after being annealed in stage III ( ~ 400°C), showed fewer single vacancies, and there was a simultaneous increase in the number of small vacancy clusters. It is concluded that stage III annealing in tungsten may be associated with the migration of single vacancies to small clusters, rather than the migration of an interstitial defect.

Atom-probe field ion microscope analysis of surfaces of materials

1989 ◽  
Vol 4 (6) ◽  
pp. 1549-1559 ◽  
Author(s):  
Tien T. Tsong ◽  
Chong-lin Chen ◽  
Jiang Liu
Keyword(s):  
Specific Binding ◽  
Atomic Layer ◽  
Atom Probe ◽  
Cluster Ions ◽  
Probe Field ◽  
Field Ion Microscopy ◽  
Semiconductor Interfaces ◽  
Compositional Changes ◽  
Ion Microscopy ◽  
Field Ion Microscope

Our recent applications of the atom-probe field ion microscope to the study of physics and chemistry of materials at the atomic level are summarized. The materials applicability of field ion microscopy has recently been extended to silicon, silicide, graphite, high Tc superconductors, and other materials. Atom-probe field ion microscopy has been used for atomic layer by atomic layer chemical analysis of surfaces in alloy and impurity segregations, for analyzing the compositional changes across metal-semiconductor interfaces, and for studying formation of cluster ions in laser stimulated field desorption. The energetics of atoms in solids and on surfaces can be studied by a direct kinetic energy analysis of field desorbed ions using a high resolution pulsed-laser time-of-flight atom-probe and by other field ion microscope measurements. The site specific binding energy of surface atoms can be measured at low temperature, where the atomic structure of the surface is still perfectly defined, to an accuracy of about 0.1 to 0.3 eV.

Characterization of Internal Interfaces by Atom Probe Field Ion Microscopy

1992 ◽  
Vol 295 ◽  
Author(s):  
M. K. Miller ◽  
Raman Jayaram
Keyword(s):  
Grain Boundaries ◽  
Compositional Analysis ◽  
Atom Probe ◽  
Probe Field ◽  
Field Ion Microscopy ◽  
Surrounding Matrix ◽  
Wide Range ◽  
Ion Microscopy ◽  
Field Ion Microscope

AbstractThe near atomic spatial resolution of the atom probe field ion microscope permits the elemental characterization of internal interfaces, grain boundaries and surfaces to be performed in a wide variety of materials. Information such as the orientation relationship between grains, topology of the interface, and the coherency of small precipitates with the surrounding matrix may be obtained from field ion microscopy. Details of the solute segregation may be obtained at the plane of the interface and as a function of distance from the interface for all elements simultaneously from atom probe compositional analysis. The capabilities and limitations of the atom probe technique in the characterization of internal interfaces is illustrated with examples of grain boundaries and interphase interfaces in a wide range of materials including intermetallics, model alloys, and commercial steels.

Nucleation and Epitaxial Growth of Vapor-Deposited Films: Electron Transmission and Field-Ion Microscopy Studies

1971 ◽  
Vol 29 ◽  
pp. 214-215
Author(s):  
L. E. Murr ◽  
O. T. Inal ◽  
H. P. Singh
Keyword(s):  
Current Knowledge ◽  
Transmission Microscopy ◽  
Field Ion Microscopy ◽  
Electron Transmission ◽  
Direct Observations ◽  
Ion Microscopy ◽  
Electron Transmission Microscopy ◽  
Critical Nuclei ◽  
Considerable Body ◽  
Field Ion Microscope

Current knowledge of the growth and structure of vapor-deposited thin films is based primarily upon experimental evidence obtained by electron diffraction and electron transmission microscopy. While a considerable body of information has been amassed, our understanding of nucleation and the occurrence of epitaxy is unclear. This disclarity arises in part because nucleation theories attempt to apply macroscopic (bulk) thermodynamic properties to small atomic aggregates on free surfaces, and because the sizes of so-called critical nuclei are deduced from extrapolations of experimental data involving observations of clusters in the electron microscope; having minimum sizes orders of magnitude larger. Clearly a fundamental understanding of nucleation and epitaxy can only be obtained by direct observations of the nature and orientation of nuclei, or of the atomic nature of the initial few atom layers of a deposit on a substrate. A potential technique for accomplishing these ends involves field-ion microscopy. This paper describes some field-ion microscope (FIM) studies of vapor-deposited Pt.

Microscopy Milestones: Field Ion Microscopy, Atom Probe Field Ion Microscopy and Atom Probe Tomography

2000 ◽  
Vol 6 (S2) ◽  
pp. 1190-1191
Author(s):  
M. K. Miller ◽  
J. A. Panitz
Keyword(s):  
Atom Probe ◽  
State University ◽  
Pennsylvania State University ◽  
Probe Field ◽  
Field Ion Microscopy ◽  
Fluorescent Screen ◽  
Positive Voltage ◽  
New Type ◽  
Ion Microscopy ◽  
Field Ion Microscope

Two of the most significant microscopy milestones that were achieved in the last century were the imaging of individual atoms and the identification of individual atoms. Both these remarkable achievements were due to Prof. E. W. Miiller and members of his group at Pennsylvania State University. Almost fifty years ago, Miiller introduced a new type of microscope in which a sharp needle-shaped specimen was pointed at a fluorescent screen, Fig. 1. By applying an appropriately high positive voltage to the specimen, image gas atoms near the apex of the specimen could be ionized and radially projected towards the screen where they produced highly magnified images of the specimen surface, Fig. 2. By cryogenically cooling the specimen and using helium as the image gas, the first images of individual atoms were obtained in a field ion microscope by Bahadur and Müller on October 11th, 1955.

scholarly journals The Interaction of O2 and Residual H on Pt Surface Studied by Field Ion Microscopy and in-situ Surface Atom Probe

2019 ◽  
Vol 26 (1) ◽  
pp. 22-29
Author(s):  
Sunwei Chen ◽  
Takumi Suzuki ◽  
Bunbunoshin Tomiyasu ◽  
Masanori Owari
Keyword(s):  
Atom Probe ◽  
Surface Atom ◽  
Field Ion Microscopy ◽  
Ion Microscopy

Field-Ion Microscopy of Tungsten Bombarded by Low-Energy Argon Ions

1972 ◽  
Vol 50 (8) ◽  
pp. 791-797 ◽  
Author(s):  
B. Gregov ◽  
R. P. W. Lawson
Keyword(s):  
Point Defects ◽  
High Voltage ◽  
Defect Density ◽  
Ion Beam ◽  
Low Energy ◽  
Field Ion Microscopy ◽  
Argon Ions ◽  
Ion Microscopy ◽  
Field Ion Microscope

The investigation of low-energy ion radiation damage in tungsten by field-ion microscopy is discussed. An experimental arrangement is described in which prepared field-ion microscope specimens may be bombarded in situ by ions from an ion gun. The background pressure in the range of 10−11 Torr allows bombardment to be carried out while the high voltage is off. Results of specimens bombarded with Ar+ ions in the 150–450 eV range at 63 °K are described. Diffusion of self-interstitials upon annealing the irradiated specimen from 63 to 78 °K has been observed. Besides point defects, clusters of vacancies and interstitials have been observed on specimens bombarded with 400 and 450 eV Ar+ ions. The irradiation-induced defect density on the side of the microscope specimen facing the ion beam is approximately double that on the far side.

Sign in / Sign up

Export Citation Format

Share Document