La0.7Ca0.3MnO3[YBa2Cu3O7-delta/La0.67Sr0.33MnO3 heterostructural devices with double coercivity have been fabricated. The superconducting critical current (I-c) 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 (I-bias) similar to I-c 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. (c) 2005 Elsevier B.V. All rights reserved.
- spin valve
- giant magnetoresistance