Competition of ferromagnetism and superconductivity in Sc3InB

TL;DR

This study investigates the electronic structure of Sc3InB, a promising superconductor candidate, predicting its non-magnetic ground state and potential superconductivity near 4.5 K, supported by theoretical calculations and preliminary experiments.

Contribution

The paper provides the first theoretical prediction of superconductivity in Sc3InB and explores the effects of vacancies and disorder on its properties.

Findings

Sc3InB exhibits a high density of states near the Fermi level.

Predicted electron-phonon coupling constant is approximately 1.

Experimental measurements show a superconducting transition near 4.5 K.

Abstract

We present results of electronic structure calculations for intermetallic perovskite Sc3InB with Full--Potential KKR-LDA method. Sc3InB is very promising candidate for a new superconductor (related to 8K MgCNi3) and can be regarded as a boron-inserted cubic Sc3In, which is a high--pressure allotropic form of the hexagonal weak ferromagnet Sc3In. We predict that cubic Sc3In can be also magnetic, whereas Sc3InB having large DOS in the vicinity of EF exhibits non-magnetic ground state. Estimation of the electron--phonon coupling for Sc3InB gives $\lambda \simeq 1$. Furthermore, the effect of vacancy in Sc3InB{1-x} and antisite disorder in Sc3(In-B) on critical parameters is also discussed in view of KKR--CPA method. All theoretical results support possibility of the superconductivity onset in Sc3InB. Preliminary experimental measurements established the transition temperature close to 4.5 K, with a very abrupt change in susceptibility and a correlated drop of the resistivity when cooling down.