Complex dielectric function of amorphous diamond films deposited by pulsed-excimer-laser ablation of graphite
- Department of Materials Science and Engineering and Materials Research Center, Northwestern University, 2225 North Campus Drive, Evanston, Illinois 60208 (United States)
Amorphous diamond films have been synthesized by pulsed excimer- (ArF)-laser ablation of graphite at room temperature. Detailed studies of the energy-dependent complex dielectric function in the energy range up to 40 eV have been carried out by Kramers-Kronig dispersion analysis of transmission electron-energy-loss spectroscopy and spectroscopic ellipsometry. Distinct from those of graphitic amorphous carbon and diamondlike carbon, the optical constants of amorphous diamond films are closely related to those of crystalline diamond, but with a smooth structure, a decrease in strength, and band shift towards lower energies. The variation of the dielectric function from crystalline diamond to amorphous diamond is analogous to that of crystalline and amorphous semiconductors such as Si and Ge. The extracted optical energy band gap reaches 2.6 eV, the highest value among the reported results for amorphous carbon films. The study of the dielectric function and its relation to the band structure of amorphous diamond films has also confirmed their diamond character. All of this information provides further evidence of the existence of amorphous diamond.
- DOE Contract Number:
- FG02-87ER45314
- OSTI ID:
- 5992503
- Journal Information:
- Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:11; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
Similar Records
Parametrized dielectric functions of amorphous GeSn alloys
Structure and optical properties of amorphous diamond films prepared by ArF laser ablation as a function of carbon ion kinetic energy
Related Subjects
360602* -- Other Materials-- Structure & Phase Studies
360606 -- Other Materials-- Physical Properties-- (1992-)
ABLATION
AMORPHOUS STATE
CARBON
DIAMONDS
DIELECTRIC PROPERTIES
ELECTRICAL PROPERTIES
ELECTRON SPECTROSCOPY
ELEMENTAL MINERALS
ELEMENTS
ENERGY DEPENDENCE
ENERGY GAP
ENERGY RANGE
ENERGY-LOSS SPECTROSCOPY
EV RANGE
EV RANGE 01-10
EV RANGE 10-100
FILMS
GRAPHITE
MINERALS
NONMETALS
PHYSICAL PROPERTIES
SPECTROSCOPY
THIN FILMS