Pseudo spin-valve behavior in oxide ferromagnet/superconductor/ferromagnet trilayers

La0.7Ca0.3MnO3/YBa2Cu3O7−δ/La0.67Sr0.33MnO3 heterostructural devices with double coercivity have been fabricated. The superconducting critical current (Ic) and critical temperature in both parallel (P) and antiparallel (AP) magnetic configurations remained unchanged within our measurement limits. This observation is contrary to results obtained elsewhere using similar metallic systems. A pseudo spin-valve magnetoresistive (MR) characteristic was observed at bias current (Ibias)∼Ic at temperatures below the onset of superconductivity. The effect increased with decreasing temperature and Ibias and can be explained using the assumption of the electron spin-charge separation.