Preface

This book covers theoretical and experimental aspects of the laser ablation phenomenon for material processing including pulsed laser deposition of thin films, laser surface modification, laser machining and laser nanoparticle formation. It also includes a study of the dynamics of plasmas generated by laser ablation of multicomponent materials and an overview of laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) techniques for chemical analysis. Chapter 1 exploits the use of the Combinatorial Pulsed Laser deposition (CPLD) method to create functional interface libraries of metal oxides by continuously modulating the composition of interfaces at the first few atomic layers to alter their functional properties. Chapter 2 presents an overview of the fabrication and applications of Transition Metal Dichalcogenides (TMDCs)-based photodetectors fabricated by the Pulsed Laser Deposition (PLD) method. It highlights the advantages and limitations of using PLD for fabricating TMDCs-based photodetectors, as well as describes unresolved problems and suggested future directions in this field. Chapter 3 presents the deposition and characterization of thin films of ZnO, MoO3 and MoO2 as well as binary oxides such as ZnO/MoO3 by the PLD method for field-effect transistor applications. Chapter 4 gives a concise overview of various laser-based surface modification processes including laser surface hardening, melting, alloying, cladding and texturing for improving the microstructure, hardness and wear resistance of mechanical components. Chapter 5 presents an excellent overview of laser beam machining techniques. It provides an easy-to-understand explanation of how lasers work, the unique properties of laser beams, types of lasers available, and applications of lasers in the machining of materials. The chapter also describes the construction of laser machining apparatus and the mechanism of material removal. Finally, it discusses the advantages and limitations of laser machining as compared to other conventional machining processes. Chapter 6 gives an overview of using laser ablation in the presence of a background gas to fabricate specific nanoparticles under non-equilibrium states. The chapter describes the mechanism of nanoparticle formation during laser ablation processes and methods to control the inter-particle spacing and patterns of nanoparticles in a film to obtain novel properties. It also describes the application of nanoparticles and thin films deposited for functional devices in several fields. Chapter 7 presents an experimental investigation and theoretical modeling of transient plasmas generated by laser ablation of complex metallic Cu-Mn-Al and Fe-Mn-Si targets. Space- and time-resolved optical emission spectroscopy and fast camera imaging were used to understand the dynamics of multicomponent plasmas. Chapter 8 gives an overview of the LIBS and LA-ICP-MS techniques. It examines the principal, instrumentation, analytical performance, data acquisition and imaging, calibration challenges and sensitivity improvement strategies for both techniques. It also provides representative examples of using LIBS and LA-ICP-MS techniques for chemical analysis in environmental, biological, medical, and forensic research.

Through these eight chapters, which include original research studies and literature reviews written by experts from the international scientific community, the reader

**II**

**Section 3**

of Memory Shape Alloys

*and Marco A.Z. Arruda*

*Stefan Toma and Doriana Forna Agop*

Plasma Generated by Laser Ablation **119**

**Chapter 7 121**

**Chapter 8 137**

Dynamics of Transient Plasmas Generated by ns Laser Ablation

Laser Chemical Elemental Analysis: From Total to Images *by Renata S. Amais, Danielle S. Francischini, Pedro S. Moreau* 

*by Stefan Andrei Irimiciuc, Norina Forna, Andrei Agop, Maricel Agop,* 

will gain a better understanding of the laser ablation process for processing materials and chemical analysis. I gratefully acknowledge all chapter authors for their enthusiastic and collaborative contributions and many thanks to Publishing Process Manager Ms. Mia Vulovic for her guidance and support in the preparation of this book.
