Type-I superconductivity in ScGa3 and LuGa3 single crystals

TL;DR

This study provides evidence that ScGa3 and LuGa3 are rare examples of type-I superconductors, characterized by low critical temperatures, specific heat phase transitions, and low Ginzburg-Landau parameters, expanding the understanding of superconducting materials.

Contribution

First demonstration of type-I superconductivity in ScGa3 and LuGa3 single crystals using magnetization, specific heat, and resistivity measurements.

Findings

Critical temperatures around 2.1-2.2 K

Field-induced phase transition observed in specific heat

Ginzburg-Landau coefficients below 0.3

Abstract

We present evidence of type-I superconductivity in single crystals of ScGa3 and LuGa3, from magnetization, specific heat, and resistivity measurements: low critical temperatures Tc = 2.1-2.2 K; field-induced secondto first-order phase transition in the specific heat, critical fields less than 240 Oe; and low Ginzburg-Landau coefficients {\kappa} approx 0.23 and 0.30 for ScGa3 and LuGa3, respectively, are all traits of a type-I superconducting ground state. These observations render ScGa3 and LuGa3 two of only several type-I superconducting compounds, with most other superconductors being type II (compounds and alloys) or type I (elemental metals and metaloids).