Type-I and type-II superconductivity in the noncentrosymmetric compound ${\mathrm{Ir}}_2{\mathrm{Ga}}_9$

We have performed magnetization, specific heat, and muon spin relaxation $\left(\mu \mathrm{SR}\right)$ measurements on single crystals of the noncentrosymmetric superconductor ${\mathrm{Ir}}_2{\mathrm{Ga}}_9$. The isothermal magnetization measurements show that there is a crossover from type-I to type-II superconductivity with decreasing temperature. Potential multiband superconductivity of ${\mathrm{Ir}}_2{\mathrm{Ga}}_9$ is observed in the specific heat data. $\mu \mathrm{SR}$ measurement is performed to map the phase diagram of ${\mathrm{Ir}}_2{\mathrm{Ga}}_9$, 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 $\mu \mathrm{SR}$ signals is observed. In addition, time reversal symmetry is found to be preserved in ${\mathrm{Ir}}_2{\mathrm{Ga}}_9$ by zero field $\mu \mathrm{SR}$ measurement.