The Magnetic Sector Atom-Probe Fim and its Applications.
Abstract
A magnetic sector atom-probe FIM (magnetic atom-probe) which is a combination of an FIM providing the atomically resolved image of the specimen and a mass spectrometer of single particle detection capability was constructed and successfully operated for studies of energy distribution of field ionization and field evaporation. The features of this instrument are: a Chevron microchannel plate employed as the ion detector displays a good portion of the entire momentum spectrum simultaneously with the resolution of better than 1/1000 and single ion sensitivity; by a simple manipulator any desired surface site of the specimen tip can be positioned toward the probe hole which is connected to the mass spectrometer. Using the energy distribution of the free-space field ionization accessible by this system, a method of field calibration was developed which is a much needed factor in analyses of FIM experiments. Reliable data of evaporation fields of various materials, such as W, Mo, Rh, Ir, Pt and Ni, were obtained. The performance of our magnetic atom-probe was tested by field evaporation experiments.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1974
- Bibcode:
- 1974PhDT.......108S
- Keywords:
-
- Physics: Atomic;
- Energy Distribution;
- Magnetic Probes;
- Mass Spectrometers;
- Ion Production Rates;
- Numerical Analysis;
- Performance Prediction;
- Instrumentation and Photography