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Non-topographic current contrast in scanning field emission microscopy
G Bertolini1, O Gürlü1, R Pröbsting1
1Laboratory for Solid State Physics, ETH Zurich, 8093 Zurich, Switzerland.
Royal Society Open Science
|July 23, 2021
Summary
Scanning Field Emission Microscopy (SFEM) reveals significant current changes due to collector material, not just topography. This finding necessitates a new understanding of electron tunneling influenced by surface material properties.
Area of Science:
- Surface science
- Quantum mechanics
- Materials science
Background:
- Scanning Field Emission Microscopy (SFEM) involves a tip near a surface, emitting electrons.
- Previous studies noted ~1% current change at monatomic surface steps (~200 pm).
Purpose of the Study:
- Investigate current changes in SFEM with varied collector materials.
- Explore non-topographic influences on field-emitted current.
- Develop a new understanding of the quantum mechanical tunneling barrier.
Main Methods:
- Preparation of surface domains with adjacent, different materials.
- Utilizing SFEM to measure field-emitted current.
- Contrasting topographic features (<15 pm) with observed current variations.
Main Results:
- Observed current contrasts as high as 10% between different collector materials.
- Demonstrated significant current dependence on collector material, independent of topography.
- Highlighted a previously unexplored factor in field emission.
Conclusions:
- Collector material significantly impacts field-emitted current in SFEM.
- Current understanding of the tunneling barrier requires revision to include collector material properties.
- This discovery opens new avenues for controlling and interpreting SFEM data.
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