Type-I/Type-II superconductivity in noncentrosymmetric compound Ir$_2$Ga$_9$

TL;DR

This study investigates the superconducting properties of Ir$_2$Ga$_9$, revealing a temperature-dependent crossover between Type-I and Type-II superconductivity, potential multi-band effects, and coexistence of both types within the same material.

Contribution

It provides the first detailed phase diagram of Ir$_2$Ga$_9$, demonstrating the coexistence of Type-I and Type-II superconductivity and suggesting multi-band superconductivity in a noncentrosymmetric compound.

Findings

Crossover from Type-I to Type-II superconductivity with decreasing temperature.

Evidence of potential multi-band superconductivity from specific heat data.

Coexistence region of Type-I and Type-II $ ext{μ}$SR signals observed.

Abstract

We have performed magnetization, specific heat, and muon spin relaxation ($\mu$SR) measurements on single crystals of the noncentrosymmetric superconductor Ir$_{2}$Ga$_{9}$. The isothermal magnetization measurements show that there is a crossover from Type-I to Type-II superconductivity with decreasing temperature. Potential multi-band superconductivity of Ir$_{2}$Ga$_{9}$~is observed in the specific heat data. $\mu$SR~measurement is performed to map the phase diagram of Ir$_{2}$Ga$_{9}$, and both Type-I and Type-II superconductivity characteristics are obtained. Most importantly, a more unique region with the coexistence of Type-I and Type-II $\mu$SR signals is observed. In addition, time reversal symmetry is found to be preserved in Ir$_{2}$Ga$_{9}$ by zero field $\mu$SR measurement.