Helium-4 adsorption to fullerenes

1998 1998

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Abstract (summary)

Since the discovery and purification of C$\sb{60}$ there has been intense research interest in fullerenes. We are exploring the adsorption behavior of $\sp4$He on fullerenes and the possibility that several of the newly discovered carbon materials provide a host environment for $\sp4$He in which the $\sp4$He properties are substantially different from the three-dimensional case. The deeper interest in this question lies in the possibility of realizing a quantum fluid in such an environment.

We are examining the possibilities of $\sp4$He intercalation into C$\sb{60}$ and into bundles of Single Wall Carbon Nanotubes (SWCNs). The former provides a cubic lattice with potential intercalation into the interstitial sites. The results presented here argue that deep penetration into the C$\sb{60}$ matrix does not occur under the conditions of this study. We do however find evidence for some excess adsorption that is independent of the C$\sb{60}$ film thickness. SWCNs might allow $\sp4$He intercalation into the insides of the tubes (if the endcaps are removed) or in between the tubes (if they are arranged parallel to each other), thus allowing for quasi one-dimensional systems of $\sp4$He. The results presented here show that $\sp4$He atoms are strongly bound to SWCNs with substantial $\sp4$He presence in the vicinity of the SWCNs for T $\sim$ 15K. A model of a 1-dimensional ideal gas with a binding energy of $\sim$330K is consistent with the low temperature data presented here.

Our experiments on $\sp4$He with C$\sb{60}$ films utilize Quartz Crystal Microbalances (QCMs) that were coated with C$\sb{60}.$ We measured the $\sp4$He mass adsorption as $\sp4$He was added under isothermal conditions or under conditions where the $\sp4$He charge in the sample cell was held constant as the temperature was varied.

The experiments of $\sp4$He in the vicinity of SWCNs use bundles of SWCNs that were stored in vacuum since purification. We measured the $\sp4$He desorption as the temperature was linearly increased from T = 14K to T = 320K.

Indexing (details)

0611: Condensation
Identifier / keyword
Pure sciences; Adsorption; Carbon nanotubes; Fullerenes; Helium-4
Helium-4 adsorption to fullerenes
Teizer, Winfried
Number of pages
Publication year
Degree date
School code
DAI-B 59/10, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
0599073896, 9780599073890
Hallock, Robert B.
University of Massachusetts Amherst
University location
United States -- Massachusetts
Source type
Dissertations & Theses
Document type
Dissertation/thesis number
ProQuest document ID
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
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