Tunneling spectroscopy and magnetization measurements of the superconducting properties of MgB2 - art. no. 220508

Cryogenic scanning tunneling microscopy and magnetization measurements were used to study the superconducting properties of MgB2. The magnetization me asurements show a sharp superconductor transition at T-c=39 K, in agreement with previous works. The tunneling spectra exhibit BCS-like gap structures , with gap parameters in the range of 5 to 7 meV, yielding a ratio of 2 Del ta /k(B)T(c)similar to3-4. This suggests that MgB2 is a conventional BCS s- wave superconductor, either in the weak-coupling or in the "intermediate-co upling' regime.