Abstract
Phase images of 20-30-nm-diam silicon spheres were collected by holographic methods in a field-emission transmission electron microscope. The spherical geometry enables the effect of specimen thickness on the electron-wave phase to be separated from the intrinsic Si electron-optical refractive effects allowing a determination of the mean inner potential Φ0. This work finds Φ0 = 11.9±0.9 V characterizing amorphous Si and 12.1±1.3 V characterizing crystalline Si. The phase images can resolve a 2-nm-thick native oxide layer and give Φ0 for SiO2=10.1±0.6 V. The phase data can quickly recognize a surface layer, and the effect of a surface layer on the determination of the bulk mean potential can be minimized.
Original language | English |
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Pages (from-to) | 1296-1298 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 70 |
Issue number | 10 |
DOIs | |
State | Published - 10 Mar 1997 |