Due to hyperthermal particle energies, extremely high pulse deposition, and quenching rates the pulsed laser deposition (PLD) lies apart from all the other known deposition methods. The paper reviews the peculiarities of the cross-beam PLD (CBPLD), one of the most effective variant of high vacuum PLD with colliding ablation plumes. In addition to the reliable reduction of any form of macroparticle contamination it allows the fabrication of films with unexpected crystalline structure and unique physical properties, making the CBPLD a unique hyperthermal energy deposition technique.
It is argued that the SWNT formation in laser-furnace technique is a kind of a liquid phase graphitization of non-graphitic forms of carbon catalyzed by molten metal-carbon nanoparticles. The melting of catalytic nanoparticles is a decisive condition for the SWNT nucleation and growth. It takes place at temperatures far below the respective eutectic temperature of the metal-carbon alloy and results from the enhanced dissolution of amorphous carbon in the metal nanoparticles. The acceleration of carbon diffusion in liquefied catalyst particles at one hand, and the competitive reduction of the free energy difference between the initial and the final carbon phases with temperature at the other hand can qualitatively explain the temperature dependencies of the SWNT yield and the observed SWNT growth rates. The results are summarized in the solid-liquid-solid model of the SWNT growth which is also applicable to the other physical and chemical methods of the SWNT synthesis.
Conference Committee Involvement (1)
Laser Applications in Microelectronic and Optoelectronic Manufacturing XII
22 January 2007 | San Jose, California, United States