Superconductivity in Pseudo-Binary Silicide SrNixSi2-x with AlB2-Type Structure

TL;DR

This paper reports the discovery of superconductivity in a pseudo-binary silicide SrNixSi2-x, which exhibits a structural phase transition and superconductivity near the phase boundary, with Ni acting as a nonmagnetic dopant.

Contribution

It reveals the emergence of superconductivity in SrNixSi2-x linked to a structural phase transition and characterizes Ni as a nonmagnetic dopant.

Findings

Superconductivity appears near the structural phase boundary.

A structural transition from cubic to hexagonal structure occurs with Ni substitution.

Ni acts as a nonmagnetic dopant confirmed by Pauli paramagnetism.

Abstract

We demonstrate the emergence of superconductivity in pseudo-binary silicide SrNixSi2-x. The compound exhibits a structural phase transition from the cubic SrSi2-type structure (P4132) to the hexagonal AlB2-type structure (P6/mmm) upon substituting Ni for Si at approximately x = 0.1. The hexagonal structure is stabilized in the range of 0.1 < x < 0.7. The superconducting phase appears in the vicinity of the structural phase boundary. Ni acts as a nonmagnetic dopant, as confirmed by the Pauli paramagnetic behavior.