STUDY OF METAL SURFACES BY THE FIELD EMISSION MICROSCOPE. Technical Report No. 9
An investigation was initiated in order to employ the energy distribution of field-emitted electrons as a means of studying the electronic band structure in metals and semiconductors. When the energy analyzer was improved in order to carry out this study, the measured energy distribution was much narrower than that predicted by the existing normal-energy distribution theory. Further investigation reveaied that the retarding potential energy analyzer which was employed measures the total electron energy rather than the energy associated with the component of velocity normal to the surface. The Fowler-Nordheim equation was derived in a new way in order to preserve the distribution in total energy of field emitted electrons. A similar derivation was carried out for thermionic emission. A striking mirror image symmetry was found between the normal-energy thermionic emission and the total-energy field emission energy distributions. A similar synnmetry was noted between the total- energy thermionic and normal-energy field emission energy distributions. Further analysis indicated that the widths of the energy distributions in field- and thermionic emission are the same. This means that field emission aad thermionic emission are now known to be on an equal footing in cases where energy distribution contributes to vacuum tube noise or to chromatic aberration in electron optics. Energy distribution measurements at liquid hydrogen, liquid nitrogen, and room temperatures were found to be in excellent agreement with the new theory. The resolution of the analyzer was 0.03 ev. Half-widths as narrow as 0.15 ev were measured and the temperature tail of the Fermi-distribution could be detected down to 77 deg K, A preliminary measurement of the total-energy distribution of thermionically emitted electrons was also carried out. (auth)
- Research Organization:
- Pennsylvania State Univ., University Park. Field Emission Lab.
- DOE Contract Number:
- AF18(600)-672
- NSA Number:
- NSA-13-009090
- OSTI ID:
- 4293112
- Report Number(s):
- AFOSR-TN-58-1136; AD-208085
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-59
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BACKGROUND- CONFIGURATION- DEFECTS- DISTRIBUTION- ELECTRIC FIELDS- ELECTRON MICROSCOPY- ELECTRON TUBES- ELECTRONS- EMISSION- ENERGY- ENERGY LEVELS- EQUATIONS- ERRORS- IMAGES- LENSES- MEASURED VALUES- METALS- SEMICONDUCTORS- SURFACES- SYMMETRY- THERMIONICS- VACUUM
DETECTION- DISTRIBUTION- ELECTRIC FIELDS- ELECTRIC POTENTIAL- ELECTRON MICROSCOPY- ELECTRONS- EMISSION- ENERGY- ENERGY LEVELS- INSTRUMENTS- LOW TEMPERATURE- MEASURED VALUES- METALS- RESOLUTION- SEMICONDUCTORS- SPECTROMETERS- SURFACES- TEMPERATURE- VELOCITY