Characterization of arachidate Langmuir-Blodgett films by variable energy positron beams

T. Marek, Csaba Szeles, K. Süvegh, E. Kiss, A. Vértes, Kelvin G. Lynn

Research output: Article

16 Citations (Scopus)

Abstract

Arachidate Langmuir-Blodgett (LB) films of different chemical composition and number of monomolecular layers deposited on silylated silica glass substrates were studied by means of positron annihilation spectroscopy. The applied methods included the measurement of the Doppler broadening of the annihilation photopeak with variable energy positron beams and bulk positron lifetime measurements. The studied samples were 58 monomolecular layers (MML) thick Mg- and Cd-arachidate, arachidic acid (50 MML) and a series of Pb-arachidate samples with 4, 10, 20, 40, and 58 MML. The investigation showed that the variable energy positron beam technique is capable of measuring the thickness of the deposited LB films. The measured positron annihilation parameters are sensitive to the chemical composition of the films and the behavior of the films in a vacuum. The results confirmed the stability of salt base LB films in high vacuum conditions and showed the desorption of pure acid films. These investigations have also shown that a strong positron trap is formed in the near-surface region of the hydrophobized substrate as a consequence of the silylation process. The results suggest that positron beams provide valuable complementary information to results obtained by other techniques.

Original languageEnglish
Pages (from-to)8189-8196
Number of pages8
JournalLangmuir
Volume15
Issue number23
DOIs
Publication statusPublished - nov. 9 1999

Fingerprint

Langmuir Blodgett films
Positrons
Langmuir-Blodgett films
positrons
Monolayers
positron annihilation
chemical composition
energy
Vacuum
Positron annihilation spectroscopy
photopeak
acids
Positron annihilation
Acids
Doppler effect
silica glass
Substrates
Fused silica
high vacuum
Chemical analysis

ASJC Scopus subject areas

  • Colloid and Surface Chemistry
  • Physical and Theoretical Chemistry

Cite this

Characterization of arachidate Langmuir-Blodgett films by variable energy positron beams. / Marek, T.; Szeles, Csaba; Süvegh, K.; Kiss, E.; Vértes, A.; Lynn, Kelvin G.

In: Langmuir, Vol. 15, No. 23, 09.11.1999, p. 8189-8196.

Research output: Article

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AU - Lynn, Kelvin G.

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