Effect of Ce content on the structure and transport properties of the Ru-1222 system

Systematic resistivity measurements, X-ray photoelectron spectroscopy (XPS) core-level studies, and Raman spectra analyses have been carried out for RuSr 2 Sm 1 + x Ce 1 − x Cu 2 O 10 − δ ( x = 0 – 0.6 ) samples. The resistivity measurements show that the transport properties of the samples changed with variation of the Ce content. XPS studies of Cu2p and O1s core levels indicate that the valence of Cu atoms increases with decreasing Ce content. Raman spectra show that the lattice parameter and the rotations of the RuO6 octahedra change slightly with Ce content.