Superconducting NbRuB derived through the fragment formalism

TL;DR

This paper demonstrates that the chemical fragment formalism can effectively guide the discovery of new superconducting materials, exemplified by the identification of NbRuB with a Tc of 3.1 K.

Contribution

It introduces the use of the fragment formalism for targeted superconductor design in the Nb-Ru-B system, showing its potential as a chemical design tool.

Findings

NbRuB is a superconductor with Tc = 3.1 K.

NbRuB is derived from specific chemical fragments with distinct B-B and B atom arrangements.

The fragment formalism aids in predicting and designing new intermetallic superconductors.

Abstract

We employ the chemical fragment formalism to perform a targeted superconductor search in the Nb-Ru-B system, yielding the orthorhombic metal-rich boride NbRuB, which displays BCS-like superconductivity with a Tc = 3.1 K. NbRuB is derived from the chemical fragments Nb3B2 + Ru3B, in which the Nb3B2 fragment contains B-B dimers and the Ru3B fragment contains isolated B atoms. A charge transfer occurs between the fragments. The results indicate that the fragment formalism is a useful chemical tool for the design of new intermetallic superconductors much the same way as the charge reservoir concept has been a useful chemical tool for the design of new copper oxide superconductors.