One or two gaps in Mo8Ga41 superconductor? Local Hall-probe magnetometry study

The magnetization properties of the endohedral cluster superconductor Mo8Ga41 are studied by sensitive Hall-probe magnetometry. The temperature dependence of the lower critical magnetic field H-c1 is obtained and compared to theoretical models accounting for single-gap and two-gap superconductivity. Data can be described by both models with minor differences. These results are confronted with our previous measurements which evidence that the system is inherently single-gap s-wave superconductor but minor additional phases are present also in seemingly perfect samples. We discuss how presence of such additional phases with varying size of the penetration depth and H-c1 field is reflected in magnetization measurements which could lead to misinterpretation of the multigap superconductivity in Mo8Ga41.

Automated summary

The magnetization properties of the endohedral cluster superconductor Mo8Ga41 were studied using sensitive Hall-probe magnetometry. The results showed that the system is inherently a single-gap s-wave superconductor with minor additional phases present in seemingly perfect samples, potentially leading to misinterpretation of multigap superconductivity in Mo8Ga41.