The effect of pressure on the superconductivity and magnetism of RuSr2GdCu2O8

A new hybrid ruthenate-cuprate superconductor RuSr2GdCu2O8 has been synthesized. This compound exhibits superconductivity and magnetic ordering around 40 K (=T-C) and 130 K (=T-m). The effect of pressure on the electrical resistance has been measured up to 2.1 GPa in order to make clear the interplay between the magnetism and the superconductivity. It is found that both T-C and T-m increase with pressure with rates of dT(C)/dP = 1.9 K GPa(-1) and dT(m)/dP = 5.7 K GPa(-1), which indicates that the superconductivity does not compete with the magnetic ordering. An x-ray diffraction experiment under pressures up to 13 GPa has been carried out in order to clarify the relation between the electronic properties and the lattice compression.