High-Temperature Superconductivity in Boron-Doped Q-Carbon

作者：Bhaumik Anagh; Sachan Ritesh; Narayan Jagdish^*

来源：ACS Nano, 2017, 11(6): 5351-5357.

DOI：10.1021/acsnano.7b01294

• superconductivity
• quenched carbon
• Raman spectroscopy
• electron energy loss spectroscopy
• secondary ion mass spectroscopy

We report high-temperature superconductivity in B-doped amorphous quenched carbon (Q-carbon). This phase is formed after nanosecond laser melting of B-doped amorphous carbon films in a super-undercooled state and followed by rapid quenching. Magnetic susceptibility measurements show the characteristics of type-II Bardeen Cooper Schrieffer superconductivity with a superconducting transition temperature (T-c) of 36.0 +/- 0.5 K for 17.0 +/- 1.0 atom % boron concentration. This value is significantly higher than the best experimentally reported Tc of 11 K for crystalline B-doped diamond. We argue that the quenching. from metallic carbon liquid leads to a stronger electron-phonon coupling due to close packing of carbon atoms with higher density of states, at the Fermi level. With these results, we propose that the non-equilibrium undercooling-assisted synthesis method can be used to fabricate highly doped materials that provide greatly enhanced superconducting properties.

• 出版日期2017-6