APPROCHES NUMÉRIQUE ET THÉORIQUE DU MICROSCOPE À FORCE ATOMIQUE‭ ‬:‭ ‬INTERACTION,‭ ‬DYNAMIQUE ET IMAGERIE

Fabien Castanié 1
1 CEMES-GNS - Groupe NanoSciences
CEMES - Centre d'élaboration de matériaux et d'études structurales
Abstract : The atomic force microscopy‭ (‬AFM‭) ‬is a powerful and versatile tool capable of imaging with a sub-nanoscale resolution,‭ ‬samples as inorganic materials surface with or without adsorbed molecules,‭ ‬and operating in environments ranging from ultrahigh vacuum‭ (‬UHV‭) ‬to solid/liquid interface.‭ ‬Among the different existing modes,‭ ‬the frequency-modulation mode of AFM‭ (‬FM-AFM‭) ‬provides remarkable results thanks to three control loops that influence self-consistently.‭ ‬In return,‭ ‬the understanding of the machine operation as well as the optimization of its settings appear tedious. Moreover,‭ ‬this difficulty is accentuated by the often complex interpretation related to specific phenomena at the nanoscale. To overcome these difficulties,‭ ‬the present thesis work consisted in the elaboration of a numerical AFM‭ (‬n-AFM‭) ‬from a program designed by L.‭ ‬Nony in C language.‭ ‬After a phase of implementation in Fortran‭ ‬90‭ ‬to ensure portability and compatibility with other scientific programs,‭ ‬new features have been developed.‭ ‬Among these,‭ ‬a coupling with a code of molecular dynamics‭ (‬MD‭) ‬was performed to consider the effects of temperature and relaxation of the imaged system. These n-AFM developments helped implement various regimes and working modes through the study of several systems.‭ ‬First,‭ ‬adsorbed bi-‭ ‬and tri-dimensional molecules helped to test the sensitivity and the stability of the n-AFM simulating a classical cantilever and tuning fork.‭ ‬Second,‭ ‬the surface reconstruction‭ ‬6H-SiC‭ (‬3X3‭) ‬was studied using the MD and then the n-AFM.‭ ‬Experimental images of this reconstruction show an atypical behavior that we tried to understand and explain.‭ ‬Finally,‭ ‬the use of the n-AFM has been extended to other areas than the study of surfaces and molecules.‭ ‬In particular,‭ ‬we modeled and studied the influence of a defect on the walls of a nano-tip oscillating at the air/liquid interface with FM-AFM.‭ ‬Finally,‭ ‬we studied the influence on the behavior of a AFM in amplitude modulation mode‭ (‬tapping mode‭) ‬of liquid nano-films on the tip-substrate system surface.‭
Complete list of metadatas


https://tel.archives-ouvertes.fr/tel-00788143
Contributor : Fabien Castanié <>
Submitted on : Friday, February 15, 2013 - 4:54:56 PM
Last modification on : Monday, April 29, 2019 - 3:42:18 PM
Long-term archiving on : Thursday, May 16, 2013 - 3:57:20 AM

Identifiers

  • HAL Id : tel-00788143, version 1

Citation

Fabien Castanié. APPROCHES NUMÉRIQUE ET THÉORIQUE DU MICROSCOPE À FORCE ATOMIQUE‭ ‬:‭ ‬INTERACTION,‭ ‬DYNAMIQUE ET IMAGERIE. Physique Numérique [physics.comp-ph]. Université Paul Sabatier - Toulouse III, 2012. Français. ⟨tel-00788143⟩

Share

Metrics

Record views

511

Files downloads

348