Investigation of pulsed laser deposited crystalline PTFE thin layer with pulsed force mode AFM

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18 Citations (Scopus)

Abstract

Teflon thin films were prepared via pulsed laser deposition using an ArF excimer laser (λ=193 nm, FWHM=20 ns) from pressed powder pellets. The applied fluence was 6.25±0.23 J/cm2, the number of pulses was 10000, the pressure in the vacuum chamber was 2×10-5 Torr and the substrate temperature was 250 °C. The layers were post-annealed at temperature within the range 320-500 °C. The atomic force microscopy and pulsed force mode atomic force microscopy (PFM) investigations demonstrated that the effective surface reaches its maximum at 320 °C. At higher temperatures (360-500 °C) it decreased significantly to an approximately constant value. Measuring the local adhesion the difference between the adhesion forces at 320 and 360 °C was kept within the error range. Increasing the annealing temperatures, the adhesion force decreased over the investigated range. Post-annealing of the samples at 360 °C resulted in highly crystalline spherulites with lateral dimensions of several hundred micrometers. By optimizing the heating and cooling rate during the annealing the average dimension of spherulites increased and ringed structures were obtained. The PFM measurements showed that the adhesion force increased significantly compared to the similar samples without ringed structures.

Original languageEnglish
Pages (from-to)239-244
Number of pages6
JournalThin Solid Films
Volume453-454
DOIs
Publication statusPublished - Apr 1 2004
EventProceedings of Symposium H on Photonic Processing of Surfaces - Strasbourg, France
Duration: Jun 10 2003Jun 13 2003

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Keywords

  • Adhesion
  • Polytetrafluoroethylene
  • Pulsed force mode atomic force microscopy
  • Pulsed laser deposition

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

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