Laser ablation composite target

Laser ablation of TiC targets was studied by De Maria et al. (1997). TiC films were realized on oriented [111] silicon. During ablation the chamber was kept under a dynamic vacuum (1.5 10 4 Pa) the laser fluence was varied in the range 0-15 J/cm2. Different ablation mechanisms, corresponding to different film characteristics, were observed related to the laser fluence values. At low fluence values (0-3 J/cm2), a film of composition TiC2 was obtained. Films obtained at 3-8 J/cm2 showed a composition close to TiC they had the best characteristics of composition, crystallinity and compactness. 

It is also possible to characterize accurately the composition of new thin fihn materials using RBS. RBS analysis of the Sri xCaxCu02 materials demonstrates that the single-phase infinite-layer thin films have the same average composition as the multiphase targets from which they were prepared by laser ablation. These compositional analysis results demonstrate that PLD can be used to prepare readily a specific stoichiometry material even when the target is not single phase. 

Another method, namely laser ablation, was first used to synthesize CNTs in 1996 hy Thess et al. [31]. In this method, a graphite target mixed with a Co and Ni catalyst is evaporated hy laser irradiation under flowing inert atmosphere at lower temperature, that is, 1200°C. The carbon products are swept by the flowing gas and deposition occurs on a water-cooled collector. Diameter and size distribution of CNTs can be controlled by adjusting the reaction temperature during the growth procedure and the catalyst composition. 

Pulsed Laser Evaporation. Laser evaporation or ablation consists of using a laser emitting at an appropriate wavelength, generally a KrF excimer laser, in a pulsed mode in a controlled atmosphere to deposit a thin film of a material the composition of which is that of the target (16—18) (see... 

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