Characterization and modification of the mechanical and surface properties at the nanoscale

• Main Author: Tam, Enrico
• Other Authors: Delplancke, Marie-Paule
• Format: Doctoral Thesis
• Language: fr
• Published: Universite Libre de Bruxelles 2009
• Subjects: Contrôle des matériaux; Sciences de l'ingénieur; Nanotechnology; Nanoelectromechanical systems; Nanocrystals; Atomic force microscopy; Nanotechnologie; Nanosystèmes électromécaniques; Nanocristaux; Microscopie à force atomique; nanoindentation; eurface enrgy; electrostatic forces; micromnipulation
• Online Access: http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210226

In the past two decades much effort has been put in the characterization of the mechanical<p>and surface properties at the nano-scale in order to conceive reliable N/MEMS<p>(Nano and Micro ElectroMechanical Systems) applications. Techniques like nanoindentation,<p>nanoscratching, atomic force microscopy have become widely used to measure<p>the mechanical and surface properties of materials at sub-micro or nano scale. Nevertheless,<p>many phenomena such us pile-up and pop-in as well as surface anomalies<p>and roughness play an important role in the accurate determination of the materials<p>properties. The first goal of this report is to study the infulence of these sources of data<p>distortion on the experimental data. The results are discussed in the first experimental<p>chapter.<p>On the other hand, conceptors would like to adapt/tune the mechanical and surface<p>properties as a function of the required application so as to adapt them to the industrial<p>need. Coatings are usually applied to materials to enhance performances and reliability<p>such as better hardness and elastic modulus, chemical resistance and wear resistance.<p>In this work, the magnetron sputtering technique is used to deposit biocompatible thin<p>layers of different compositions (titanium carbide, titanium nitride and amorphous<p>carbon) over a titanium substrate. The goal of this second experimental part is the<p>study of the deposition parameters influence on the resulting mechanical and surface<p>properties.<p>New materials such as nanocrystal superlattices have recently received considerable<p>attention due to their versatile electronic and optical properties. However, this new<p>class of material requires robust mechanical properties to be useful for technological<p>applications. In the third and last experimental chapter, nanoindentation and atomic<p>force microscopy are used to characterize the mechanical behavior of well ordered lead<p>sulfide (PbS) nanocrystal superlattices. The goal of this last chapter is the understanding<p>of the deformation process in order to conceive more reliable nanocrystal<p>superlattices. === Doctorat en Sciences de l'ingénieur === info:eu-repo/semantics/nonPublished