SEIRA Spektroskopi

Jesper Heebøll-Christensen, Louise Brinck & Siemen Baader

Student thesis: Termpaper

Abstract

Abstract I dette rapport beskrives de teorier, der er fremsat for molekylers øgede absorptionsevne i det midt-infrarøde område, når de appliceres til et substrat, der er coatet med en tynd metalfilm. Denne effekt kaldes surface-enhanced infrared absorption (SEIRA). Vi undersøger eksperimentelt, ved transmissionsspektroskopi, om det er muligt at eftervise SEIRA for p-NBA appliceret til et calciumflouridvindue coatet med guldfilm i tykkelserne 4.5 nm, 8 nm og 16 nm. Desuden undersøger vi reproducerbarheden af hver måleserie. Vi finder, at der er en forstærkning i absorptionen af p-NBA, som kan tilskrives en SEIRA effekt, og at denne forstærkning bliver større i takt med, at guldfilmene bliver tykkere. Det konkluderes at reproducerbarheden er tilstrækkelig til at dokumentere en forstærkning. Abstract in English In this report we describe the theories for the increased infrared absorption ability of molecules applied to a substrate coated with a thin metal film. This effect is called surface-enhanced infrared absorption (SEIRA). With transmission spectroscopy we experimentally examine the possibilities for documententation of SEIRA for p-NBA applied to a calciumflouride window coated with goldfilms with thicknesses of 4.5 nm, 8 nm and 16 nm. Furthermore we examine the reproducibility of each series. We find that there is an enhancement in the absorption of p-NBA which can be ascribed to a SEIRA effect and that this enhancement is increased with increased gold film thickness. It is concluded that the reproducibility is sufficient for documentation of the enhancement.

EducationsPhysics, (Bachelor/Graduate Programme) Graduate
LanguageDanish
Publication date1 Jan 2004
SupervisorsNiels Boye Olsen

Keywords

  • eksperiment
  • SEIRA
  • infrarød
  • Risø
  • metallag
  • spektroskopi
  • metaløer