Superconductivity in a Scandium Borocarbide with a Layered Crystal Structure

Abstract

The discovery of nearly room-temperature superconductivity in superhydrides has motivated further materials research for conventional superconductors. To realize the moderately high critical temperature $(T_{\mathrm{c}})$ in materials containing light elements, we explored new superconducting phases in a scandium borocarbide system. Here, we report the observation of superconductivity in a new ternary Sc-B-C compound. The crystal structure, which was determined through a Rietveld analysis, belongs to tetragonal space group $P4/ncc$. By complementarily using the density functional theory calculations, a chemical formula of the compound was found to be expressed as Sc${}_{20}$C${}_{8-x}$B${}_x$C${}_{20}$($x=1\mathrm{or}2$). Interestingly, a small amount of B is essential to stabilize the present structure. Our experiments revealed the typical type-II superconductivity at $T_{\mathrm{c}}=7.7\mathrm{K}$. Additionally, we calculated the density of states within a first-principles approach and found that the contribution of the Sc-3d orbital was mainly responsible for the superconductivity.

13 pages, 3 tables, 8 figures

References in corpus (1)

• Superconductivity in Heavy Alkaline-Earths Intercalated Graphites

Cited by in corpus (3)

• Universal Fermi velocity in highly compressed hydride superconductors
• Experimental and Computational Determination of Optimal Boron Content in Layered Superconductor Sc${}_{20}$C${}_{8-x}$B${}_x$C${}_{20}$
• Superconductivity in Scandium Borocarbide with orbital hybridization