Inelastic light scattering studies of superconducting Ru-based double perovskites

We report an inelastic light scattering study of double perovskite structure Sr2Y(Ru1-xCux)O6 systems as a function of temperature and doping (x=0.0, 0.05, and 0.1). As the temperature is lowered, for x=0.0, the 767 cm-1 A1g apical oxygen phonon mode exhibits a softening and an enhancement of the linewidth in the antiferromagnetic phase. Similar anomalies are also observed for x=0.1 when the superconducting gap opens. This suggests that a strong lattice-spin-charge coupling plays an important role in the magnetic and superconducting properties observed in these materials