Direct observation and mechanism of increased emission sites in Fe-coated microcrystalline diamond films

Journal Article · Fri Jun 15 04:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4729836· OSTI ID:22089252

Panda, Kalpataru; Sundaravel, B.; Panigrahi, B. K. ^[1]; Huang, Pin-Chang; Shih, Wen-Ching ^[2]; Chen, Huang-Chin; Lin, I-Nan ^[3]

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1. Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)
2. Graduate Institute in Electro-Optical Engineering, Tatung University, Taipei 104, Taiwan (China)
3. Department of Physics, Tamkang University, New-Taipei 251, Taiwan (China)

The electron field emission (EFE) properties of microcrystalline diamond (MCD) films are significantly enhanced due to the Fe coating and post-annealing processes. The 900 Degree-Sign C post-annealed Fe coated diamond films exhibit the best EFE properties, with a turn on field (E{sub 0}) of 3.42 V/{mu}m and attain EFE current density (J{sub e}) of 170 {mu}A/cm{sup 2} at 7.5 V/{mu}m. Scanning tunnelling spectroscopy (STS) in current imaging tunnelling spectroscopy mode clearly shows the increased number density of emission sites in Fe-coated and post-annealed MCD films than the as-prepared ones. Emission is seen from the boundaries of the Fe (or Fe{sub 3}C) nanoparticles formed during the annealing process. In STS measurement, the normalized conductance (dI/dV/I/V) versus V curves indicate nearly metallic band gap, at the boundaries of Fe (or Fe{sub 3}C) nanoparticles. Microstructural analysis indicates that the mechanism for improved EFE properties is due to the formation of nanographite that surrounds the Fe (or Fe{sub 3}C) nanoparticles.

• OSTI ID: 22089252
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 12 Vol. 111; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
CHEMICAL VAPOR DEPOSITION
CURRENT DENSITY
DIAMONDS
ENERGY GAP
FIELD EMISSION
GRAPHITE
IRON CARBIDES
MAGNETIC CIRCULAR DICHROISM
MICROSTRUCTURE
NANOSTRUCTURES
PLASMA
SCANNING TUNNELING MICROSCOPY
SPECTROSCOPY
THIN FILMS
TUNNEL EFFECT