Pulsed laser ablation deposition technique

Pulsed laser ablation deposition technique (PLAI) technique)... 

Figure 6.17. Scheme, according to Roman etal. (1997), of the deposition of nano-laminate coatings via the pulsed laser ablation technique. 1 Vacuum, chamber, 2 Ti-6A1-4V substrate holder and heater, 3 deposit (nanometer range), 4 laser-induced plasma, 5 target (TiB2/TiN),... 

The particle size distribution may be controlled in both laser ablation/vaporization techniques by manipulating the pulse energy/duration (usually in the timeframe of 10-50 ns/pulse). It should be noted that when laser ablation is used for thin-film deposition, the technique is referred to as pulsed-laser deposition (PLD). At lower operating pressures ca. <0.1 Torr), thin films will be favored however, at higher pressures ca. >1 Torr), nanoparticles will be formed due to a greater opportunity for gas-phase nucleation to occur. 

Flash evaporation can also be done with the pulsed laser vaporization of surfaces.f This technique is sometimes called laser ablation deposition (LAD) or pulsed laser deposition (PLD). Typically an excimer laser (YAG or ARF) is used to deposit energy in pulses. The YAG lasers typically deliver pulses (5 ns, 5 Hz) with an energy of about J/pulse and the ARF lasers typically deliver pulses (20 ns, 50 Hz) with about 300nJ/ pulse. 

Another recent, nontraditional investigation involved the use a of pump-probe technique to study the laser-ablation of tooth enamel [80] and the influence of an optically thick water layer applied onto the tooth surface [81]. Laser ablation was performed in the presence and absence of water, and synchrotron FT-IRM used to probe the chemical composition of the enamel in the thus-formed crater. FT-IRM revealed the formation of new mineral phases deposited along the crater walls after repetitive laser pulses, while the nonapatitic phases reduced the efflciency of... 

During the last decade, processing of polymers has become an important field of applied and fundamental research [48]. One of the most important fields is laser ablation involving various techniques and applications. Laser ablation is used as an analytical tool for MALDI (matrix-assisted laser de-sorption/ionization) [28, 29] and LIBS (laser-induced breakdown spectroscopy) [49] or as a preparative tool for PLD (pulsed laser deposition) of inorganic materials [37] and of synthetic polymer films [50, 51]. Another application is surface modification of polymers [52] if low fluences are applied, the polymer surface can be either chemically modified to improve adhesion... 

Two recent techniques that have come to be applied to compound semiconductors and oxides are pulsed laser deposition (PLD) also known as laser ablation [6] and ion beam assisted deposition (IBAD) [2-8]. These techniques have been developed for films whose elemental constituents are not easily volitalized in elemental or organome-tallic forms or whose formation can benefit from the added energy imparted to the reactants by the process. 

Several deposition techniques have been investigated such as laser ablation, pulsed laser deposition, electrostatic spray and sputtering [127]. Orlovskaya and co-workers utilised Raman spectroscopy in conjunction with SEM, XRD, and energy dispersive X-ray analysis to study the structural properties of a 200 nm thick LaCrOa protective thin film deposited on high temperature steels by radiofrequency magnetron sputtering [126]. Fig. 12(a) shows the Raman spectrum of the polished stainless steel surface... 

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