Symmetry-breaking in the H2@C60endofullerene revealed by inelastic neutron scattering at low temperature
The fine structure of the rotational ground state of molecular ortho-hydrogen confined inside the fullerene cage C60 is investigated by inelastic neutron scattering (INS). The INS line corresponding to transitions between the three sub-levels comprising the ortho ground state to the non-degenerate p...
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Royal Society of Chemistry
2015
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| Online Access: | https://eprints.nottingham.ac.uk/34667/ |
| _version_ | 1848794906608271360 |
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| author | Mamone, Salvatore Johnson, Mark R. Ollivier, Jacques Rols, Stéphane Levitt, Malcolm H. Horsewill, Anthony J. |
| author_facet | Mamone, Salvatore Johnson, Mark R. Ollivier, Jacques Rols, Stéphane Levitt, Malcolm H. Horsewill, Anthony J. |
| author_sort | Mamone, Salvatore |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | The fine structure of the rotational ground state of molecular ortho-hydrogen confined inside the fullerene cage C60 is investigated by inelastic neutron scattering (INS). The INS line corresponding to transitions between the three sub-levels comprising the ortho ground state to the non-degenerate para ground state was studied as a function of temperature down to 60 mK in neutron energy gain. The experiments show that at ambient pressure the three ortho sub-levels are split into a low energy non-degenerate level and a high energy doubly degenerate level separated by 0.135 ± 0.010 meV. This observation is consistent with hydrogen molecules being located at sites with axial symmetry superseding the icosahedral symmetry of isolated rigid C60 cages in the solid phase. To gain insight into the role of inter-cage interactions in determining the symmetry breaking potential, the effects of hydrostatic pressure on the fine structure of the line was also investigated. The analysis of the INS spectra shows that the potential and the energy levels of H2 are sensitive to the orientation of neighbouring cages, consistent with the low-temperature crystalline phase of C60. |
| first_indexed | 2025-11-14T19:23:38Z |
| format | Article |
| id | nottingham-34667 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:23:38Z |
| publishDate | 2015 |
| publisher | Royal Society of Chemistry |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-346672020-05-04T17:27:06Z https://eprints.nottingham.ac.uk/34667/ Symmetry-breaking in the H2@C60endofullerene revealed by inelastic neutron scattering at low temperature Mamone, Salvatore Johnson, Mark R. Ollivier, Jacques Rols, Stéphane Levitt, Malcolm H. Horsewill, Anthony J. The fine structure of the rotational ground state of molecular ortho-hydrogen confined inside the fullerene cage C60 is investigated by inelastic neutron scattering (INS). The INS line corresponding to transitions between the three sub-levels comprising the ortho ground state to the non-degenerate para ground state was studied as a function of temperature down to 60 mK in neutron energy gain. The experiments show that at ambient pressure the three ortho sub-levels are split into a low energy non-degenerate level and a high energy doubly degenerate level separated by 0.135 ± 0.010 meV. This observation is consistent with hydrogen molecules being located at sites with axial symmetry superseding the icosahedral symmetry of isolated rigid C60 cages in the solid phase. To gain insight into the role of inter-cage interactions in determining the symmetry breaking potential, the effects of hydrostatic pressure on the fine structure of the line was also investigated. The analysis of the INS spectra shows that the potential and the energy levels of H2 are sensitive to the orientation of neighbouring cages, consistent with the low-temperature crystalline phase of C60. Royal Society of Chemistry 2015-12-11 Article PeerReviewed Mamone, Salvatore, Johnson, Mark R., Ollivier, Jacques, Rols, Stéphane, Levitt, Malcolm H. and Horsewill, Anthony J. (2015) Symmetry-breaking in the H2@C60endofullerene revealed by inelastic neutron scattering at low temperature. Physical Chemistry Chemical Physics, 18 (3). pp. 1998-2005. ISSN 1463-9076 http://dx.doi.org/10.1039/c5cp07146a 10.1039/c5cp07146a 10.1039/c5cp07146a 10.1039/c5cp07146a |
| spellingShingle | Mamone, Salvatore Johnson, Mark R. Ollivier, Jacques Rols, Stéphane Levitt, Malcolm H. Horsewill, Anthony J. Symmetry-breaking in the H2@C60endofullerene revealed by inelastic neutron scattering at low temperature |
| title | Symmetry-breaking in the H2@C60endofullerene revealed by inelastic neutron scattering at low temperature |
| title_full | Symmetry-breaking in the H2@C60endofullerene revealed by inelastic neutron scattering at low temperature |
| title_fullStr | Symmetry-breaking in the H2@C60endofullerene revealed by inelastic neutron scattering at low temperature |
| title_full_unstemmed | Symmetry-breaking in the H2@C60endofullerene revealed by inelastic neutron scattering at low temperature |
| title_short | Symmetry-breaking in the H2@C60endofullerene revealed by inelastic neutron scattering at low temperature |
| title_sort | symmetry-breaking in the h2@c60endofullerene revealed by inelastic neutron scattering at low temperature |
| url | https://eprints.nottingham.ac.uk/34667/ https://eprints.nottingham.ac.uk/34667/ https://eprints.nottingham.ac.uk/34667/ |