To design an ambient-temperature and ambient-pressure superconductor inspired by diamond, I must exploit its winning characteristics—extremely rigid covalent bonds, light atoms (carbon), very high Debye temperature (~2200 K), and high-energy optical phonons (up to ~160 meV)—while overcoming its fundamental limitation: pure diamond is a wide-gap insulator. The idea is therefore to “open up” the diamond framework into a nanoporous structure, preserving the sp³ connectivity, and to insert dopants that render it metallic with strong electron–phonon coupling.The proposed material: type-I clathrate Li₈B₈C₃₈Inspiration from diamond Diamond owes its exceptional properties to the three-dimensional network of sp³ C–C bonds, which is the stiffest “scaffold” known. If I can build an equally rigid but hollow structure, in which the carbon–carbon bonds remain intact and the whole architecture retains a high Debye temperature, I can then fill the cavities with charge-donating atoms, transforming the system into a metal without softening the host matrix. This is precisely the concept of clathrates: cages of light atoms welded together by covalent bonds, which trap guest ions.
Giustino Travaglini (Thu,) studied this question.