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Projects / Programmes source: ARIS

Electron field emission from flat nanostructured cathodes

Research activity

Code Science Field Subfield
2.09.00  Engineering sciences and technologies  Electronic components and technologies   

Code Science Field
T150  Technological sciences  Material technology 
Keywords
flat broad area field emission cathodes, field emission, nanostructured materials
Evaluation (rules)
source: COBISS
Researchers (5)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  08028  Miha Kocmur    Technical associate  2007 - 2009  15 
2.  15703  PhD Janez Kovač  Electronic components and technologies  Researcher  2007 - 2009  683 
3.  03066  PhD Vincenc Nemanič  Electronic components and technologies  Head  2007 - 2009  246 
4.  20335  PhD Bojan Zajec  Civil engineering  Researcher  2007 - 2009  185 
5.  03366  Marko Žumer  Electronic components and technologies  Researcher  2007 - 2009  110 
Organisations (1)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0106  Jožef Stefan Institute  Ljubljana  5051606000  91,992 
Abstract
We intend to study electron field emission from nanostructured flat broad area field emission cathodes. The main target is to identify individual field emission sites by complementary studies of their chemical composition, shape and other parameters influencing the emission properties. By means of our newly developed microscopic technique we are able to register the emission pattern and to determine emission current from any individual site located on the surface of 25 mm diameter cathodes. We intend to get original data on two novel types of cathodes. The first type is directly on substrate grown inorganic nanotube film synthesised at Jozef Stefan Institute. The second types are films of nanostructured carbon materials (nano-crystalline diamond and aligned carbon nanotube (CNT) films). These later types are synthesized at North Carolina State University. However, there is still significant disagreement on the origin of the field enhancement. For instance, nanocrystalline diamond films have relatively flat surfaces (AFM RMS values of 20 nm or less), yet they display field emission at applied fields of less than 2 V/µm. The geometric structure of the CNTs seems to be a natural explanation of the emission properties, but several studies suggest that a very low fraction of the tubes actually contribute to the emission. In addition to the prospect of efficient field emission, both classes of materials to be used in this research should be chemically inert and thus suitable for long term operation in high vacuum. Their application is planned to be in several “high-tech” devices, like flat electronic displays, miniature x-ray tubes, electron microscopes, mass spectrometers etc.
Significance for science
The scientific relevance of our results is evidently their publication in specialized highly ranked journals. The main message of our research is that inorganic nanowires synthesized at Jozef Stefan Institute represent an interesting group of nanostructured materials that exhibit quite intense field emission. In some aspects, they can compete with carbon nanotubes, declared as the best field emission source of electrons. Another important fact is that results represent a collaborative work between internationally recognized groups. The present project thus enabled exchange of fresh ideas. Most of results in the group were realized by equipment that was designed for specific need of the present project. It is also well known that building of such equipment is a time consuming work. Anyhow, the new instrumental methods will enable further investigation in the field of new materials with high electron emissivity. The project thus enabled to increasing the group capability for future investigations.
Significance for the country
At present, we are the only research group in Slovenia capable to perform investigation of field emission and thermionic emission from modern nanostructured materials, as described above. The three year project contributed a part of the budget that enabled activity and survival of the group. We have a good background for future scientific international cooperation as well as with the segment of Slovenian industry that sell products worldwide.
Most important scientific results Annual report 2008, final report, complete report on dLib.si
Most important socioeconomically and culturally relevant results Annual report 2008, final report, complete report on dLib.si
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