Pressure dependence of Tc in the MgB2 superconductor as probed by resistivity measurements

High-pressure resistivity experiments were performed on the recently discovered superconductor, MgB2. T-c decreases quasi-linearly with applied pressure to 1.4 GPa at a rate of -2.0(1) K CPa-1, which is somewhat larger than that derived from ac susceptibility measurements. The reduction of T-c is consistent with the BCS picture, in a similar way to the C-60-based superconductors. Taking into account the pressure dependence of the unit cell volume, V, the volume coefficient of T-c, d(ln T-c) / dV is significantly large.