We present the observation of magnetoresistance in Co/Ca/Alq3/Ca/NiFe spin-valve devices. Thin Ca layers contacting 150 nm thick Alq3 enable the injection of spin-polarized electrons into Alq3 due to engineering of the band alignment. The devices exhibit symmetric current-voltage (I-V) characteristics indicating identical metal contacts on Alq3 and up to 4% of positive magnetoresistance was observed at 4.5K. In contrast, simultaneously fabricated Co/Alq3/NiFe devices displayed asymmetric I-V curves due to the different metal electrodes, and spin-valve effects were not observed above noise level.
Citation: Applied Physics Letters
Pub Type: Journals