  X-ray absorption spectroscopy(XAS) Ru L-edge and O K-edge measurements on
single crystals of Sr2YRu1-xCuxO6 (x=0.01-0.05) solid solutions show that Cu
replaces Ru in the lattice which results in a lattice distortion and itinerant
holes that increase with increasing x. Powder X-ray diffraction (XRD)
measurements confirm the lattice distortion through changes in the lattice
parameters. Magnetic measurements reveal an antiferromagnetic transition at 32
K in the crystals with x=0 and a diamagnetic transition at 32 K for x \geq
0.01indicative of superconductivity in the zero field cooled (ZFC) curves. The
field cooled (FC) curves show a weak ferromagnetic character with x=0 and a
ferromagnetic transition at 30 K and an antiferromagnetic transition at 23 K in
the presence of Cu. The peak at 30 K in the ac susceptibility measurements
indicates a spin-glass behavior. The low field part of the M-H curve for x=0.05
crystal indicates weak superconductivity. The shifting of the M-H curve on FC
indicates spin-glass state. In conjunction with the XAS results the magnetic
behavior is explained in terms of a spontaneous vortex state as a result of the
non-freezing Ru5+ spins.
