Phase diagram of 4He film in 3D nanopores of ZTC

Yuna Nakashima, Taku Matsushita, Mitsunori Hieda, Nobuo Wada, Hirotomo Nishihara, Takashi Kyotani

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

In the study to examine effects of three-dimensional (3D) film connectivity on superfluid 4He film in the pore network, we have measured heat capacities of 4He film adsorbed in zeolite templated carbon (ZTC), which is an assembly of graphene fragments and has network of 1.2 nm pore with the 3D period of 1.4 nm, shorter than those of nanoporous materials studied so far. From the heat of desorption, the 4He film adsorbed in ZTC was observed to be formed up to about 1.4 atomic layers. Heat capacities of the 4He film are rather similar to those on SiO 2-based porous materials than those on graphite, except for large heat capacities of monolayer 4He film. At low coverages, the heat capacity rapidly decreases below a temperature T L, suggesting a localized state of 4He at T<T L. The T L almost monotonically lowers with increasing the coverage. Heat capacity isotherms show maxima around 1.1 layers, which suggests quantum degenerate fluid (Bose fluid) above the coverage. From these results, the phase diagram of 4He film adsorbed in ZTC has been determined.

Original languageEnglish
Pages (from-to)565-572
Number of pages8
JournalJournal of Low Temperature Physics
Volume162
Issue number5-6
DOIs
Publication statusPublished - 2011 Mar

Keywords

  • 3D nanopores
  • He film
  • Phase diagram
  • Restricted geometry
  • Zeolite templated carbon (ZTC)

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)
  • Condensed Matter Physics

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