Ammonia sensing properties of multiwalled carbon nanotubes embedded in porous alumina templates

Raghu Mangu, Suresh Rajaputra, Patricia Clore, Dali Qian, Rodney Andrews, Vijay P. Singh

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Highly ordered anodic aluminum oxide templates were fabricated by a two step anodization process. Vertically aligned multiwalled carbon nanotube (MWCNT) arrays were grown in these templates through xylene pyrolysis, without the use of a catalyst and were integrated into a resistive sensor design. An equivalent circuit model was developed to understand the operation and to propose design changes for increased sensitivity. During the xylene pyrolysis, a thin layer of amorphous carbon (5-50 nm), forms on both sides of the template as a by-product of the CVD process. This a-C layer plays a crucial role in determining baseline resistance and the sensitivity, since it affects the current path. A study was undertaken to elucidate the dependence of sensitivity on the thickness of amorphous carbon layers, by subjecting the device to post-processing step of plasma oxidation.

Original languageEnglish
Pages (from-to)2-8
Number of pages7
JournalMaterials Science and Engineering B: Solid-State Materials for Advanced Technology
Issue number1-3
StatePublished - Oct 25 2010


  • Anodic aluminum oxide
  • CVD
  • Carbon nanotubes
  • Gas sensor

ASJC Scopus subject areas

  • Materials Science (all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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