Effect of pressure on the superconducting transition temperature of doped and neutron-damaged MgB2

摘要

Measurements of the superconducting transition temperatures for Al-doped,C-doped and neutron-damaged-annealed MgB2 samples under pressure up to ~8 kbarare presented. The dT_c/dP values change systematically with the decrease ofthe ambient pressure T_c in a regular fashion. The evolution of the pressurederivatives can be understood assuming that the change in phonon spectrum is adominant contribution to dT_c/dP.