Search for near room-temperature superconductivity in B-doped Q-carbon

ABSTRACT

We present 1D, 2D and 3D structures of boron-doped Q-carbon with a higher superconducting transition temperature than the current value of 55 K in 25 at% B-doped amorphous Q-carbon. The higher transition temperature is predicted for 1D and 2D crystalline structures with increasing density of states near the Fermi level through dopant trapping in substitutional sites. We have synthesized 50at% B-doped Q-carbon where diamond tetrahedra are arranged randomly and packed with over 80% efficiency to generate an amorphous structure. Detailed EELS measurements show higher density of states near the Fermi level above 90 K and preliminary transport data show signature of T_c above 100 K.

GRAPHICAL ABSTRACT

IMPACT STATEMENT

Novel 1D, 2D and 3D structures of boron-doped Q-carbon with higher Tc than current BCS record of 55K by increasing B-concentration and the density of states near the Fermi level.

KEYWORDS:

• High-temperature superconductors
• Q-carbon
• BCS superconductivity
• Cryo-EELS

Acknowledgements

We are grateful to Fan Family Foundation Distinguished Chair Endowment for Professor J. Narayan.. We are also very pleased to acknowledge the technical help of A. Moatti and useful discussions with Professors Marvin Cohen, John Prater, and Roger Narayan.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Ritesh Sachan acknowledges the National Academy of Sciences (NAS), USA for awarding the NRC research fellowship This work was supported by Defense Science Office (NR00111820033), National Science Foundation [DMR-1735695] and Army Research Office [grant number W911NF-17-1-0596].