Superconductivity at 3.1 K in the orthorhombic ternary silicide ScRuSi

TL;DR

This study reports the discovery of superconductivity at 3.1 K in the orthorhombic ternary silicide ScRuSi, including its synthesis, structure, and physical properties, marking it as the first Co2P-type superconductor with scandium.

Contribution

The paper presents the first observation of superconductivity in the Co2P-type ScRuSi compound, expanding the family of scandium-containing superconductors.

Findings

Superconducts below 3.1 K with type-II behavior

Bulk superconductivity confirmed by magnetization and specific heat

Transformation to a non-superconducting hexagonal phase upon annealing

Abstract

We report the synthesis, crystal structure, superconductivity and physical property characterizations of the ternary equiatomic compound ScRuSi. Polycrystalline samples of ScRuSi were prepared by an arc-melting method. The as-prepared samples were identified as the orthorhombic Co2P-type o-ScRuSi by the powder X-ray diffraction analysis. Electrical resistivity measurement shows o-ScRuSi to be a metal which superconducts below a Tc of 3.1 K, and the upper critical field {\mu}0Hc2(0) is estimated to be 0.87 T. The magnetization and specific heat measurements confirm the bulk type-II superconductivity in o-ScRuSi, with the specific heat jump within the BCS weak coupling limit. o-ScRuSi is the first Co2P-type superconductor containing scandium. After annealing at 1273 K for a week, o-ScRuSi transforms into the hexagonal Fe2P-type h-ScRuSi, and the latter is a Pauli-paramagnetic metal with no superconductivity observed above 1.8 K.