High-pressure study on MgB2 -: art. no. 012507

The hydrostatic pressure effect on the newly discovered superconductor MgB2 has been determined. The transition temperature T-c was found to decrease linearly at a large rate of -1.6 K/GPa, in good quantitative agreement with the ensuing calculated value of -1.4 K/GPa within the BCS framework by Loa and Syassen, using the full-potential linearized augmented plane-wave method. The relative pressure coefficient d In T-c/dp for MgB2 also falls between the known values for conventional sp and d superconductors. The observation, therefore, suggests that electron-phonon interactions play a significant role in the superconductivity of the compound.