Formation of one-dimensional quantum crystals of molecular deuterium inside carbon nanotubes. (30th April 2021)

• Record Type: Journal Article
• Authors: Cabrillo, Carlos; Fernández-Perea, Ricardo; Bermejo, Francisco Javier; Chico, Leonor; Mondelli, Claudia; González, Miguel A.; Enciso, Eduardo; Benito, Ana M.; Maser, Wolfgang K.
• Is Part Of: Carbon. Volume 175(2021)
• Page Start: 141
• Page End: 154
• Publication Date: 2021-04-30
• Subjects: Quantum solids -- 1D crystals -- Confinement -- Molecular hydrogen -- Neutron scattering; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2020.12.067
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Crystallization under stringent cylindrical confinement leads to novel quasi-one-dimensional materials. Substances with strong cohesive interactions can eventually preserve the symmetries of their bulk phase compatible with the restricted geometry, while those with weak cohesive interactions develop qualitatively different structures. Frozen molecular deuterium (D2 ), a solid with a strong quantum character, is structurally held by weak dispersive forces. Here, the formation of one-dimensional D2 crystals under carbon nanotube confinement is reported. In contradiction with its weak cohesive interactions, their structures, scrutinized using neutron scattering, correspond to definite cylindrical sections of the hexagonal close-packed bulk crystal. The results are rationalized on the grounds of numerical calculations, which point towards nuclear quantum delocalization as the physical mechanism responsible for the stabilization of such outstanding structures. Graphical abstract: Image 1 Highlights: Neutron scattering allows structural studies of D2 confined within MWCNTs. D2 within MWCNTs solidifies forming ordered crystals down to the strict 1D limit. Crystallization of D2 within MWCNTs preserves the structure of the bulk D2 crystal. The D2 1D-crystals retain the strong quantum character of the bulk D2 solid. Strong evidence of Quantum Nuclear Effects as essential for the 1D-crystal stability.