**2. Preparation**

different. At low intensities and high duration of the interaction of the radiation with the solid absorbing target, only heating of the target occurs. Increasing the intensity of the radiation can lead to the reaching of the melting temperature and to the further evaporation of the substance of the target. Under powerful pulse laser radiation, the evaporation of the substance occurs with the formation of plasma cloud that contains ions, clusters and small particles. For such an "explosive" evaporation, the term "laser ablation" (from Lat. "ablatio"—taking, removal) is used. Sometimes in the literature, the term "ablation" is interpreted more widely, covering the removal of substances from the surface as a result of any physical and chemical processes that occur under high-energy impact on the object. In the present chapter, the term "ablation" will be used only forthe threshold process of explosive vaporization of material from a surface of solid targets with the formation of gas (vapor) plasma cloud via the rapid absorption of

246 Applications of Laser Ablation - Thin Film Deposition, Nanomaterial Synthesis and Surface Modification

First of all, the process of pulsed laser ablation (PLA), when micro-, nano- and later femtosecond pulses are exposed to the target, had found a successful application in laser materials processing for punching, marking and precise removal of layers of material in electronics [1]. Next, the PLA in gas phase and vacuum became successfully used for atomization of targets

Using PLA of bulk targets in liquids to obtain nanoparticles (NPs) was initiated by the rapid development of nanotechnology in the 1990s of the twentieth century. The first deliberate use of this technique for the synthesis of nanocolloids took place in 1993 when the dispersions of Ag, Au, Pt, Pd and Cu nanoparticles in water and organic solvents for the surface-enhanced

Over the past two decades, pulsed laser ablation in liquids (PLAL) has become an effective and popular tool for obtaining nanosized materials. The absence of a mechanical interaction in the synthesis process and the ability to prepare "pure" nanoparticles without additional chemicals in the pure solvents straightaway in the form of stable colloids make this method very attractive for biological and medical applications. Catalysis, electronics and nonlinear optics are also the areas where the nanocolloids synthesized by the PLAL method and nanocrystalline powder obtained via further drying of the dispersions are used. The relatively simple experimental technique and the possibility of obtaining different types of nanoparticles (from metals to ceramics and polymers) on the same installation make this method a suitable tool for obtaining nanomaterials for the study of fundamental properties of substances in the nanostate. An opportunity to change the parameters of laser pulses and use various solvents with additives of precursors provides additional options to vary the composition, structure

As of now, thousands of original research works, reviews and monographs on various aspects of the PLAL for the synthesis of nanostructures have been published [6–8]. They consider common mechanisms of PLAL and obtaining and characterization of specific nanomaterials as well. However, the interest in such research work continues unabated. On the one hand, this is due to the demand for nanomaterials with specific functional properties for various applications. On the other hand, there are three main aims that have not been achieved yet: effective control of structure and dimensional characteristics of nanoparticles obtained;

energy of high-power laser pulses in a limited volume.

Raman scattering (SERS) spectroscopy were obtained [5].

and dimensional characteristics of the nanoparticles obtained.

in mass spectrometry, obtaining thin films and ultrafine powders [2–4].
