Published online by Cambridge University Press: 01 February 2011
We have prepared layered sandwich structures composed of Co / organic materials / La0.67Sr0.33MnO3 and measured the magnetic field effect on electrical resistance. We inserted various OMs including pentacene, C60, 8-hydroxy-quinoline aluminum and titanyl-phthalocyanine with a thickness in the range from 200 nm to 1,000 nm. All devises prepared showed clear spin-valve characteristics with magneto-resistance (MR) ratios of approximately a few to 10% at low temperature. It was found that spins were transported in rather thick organic films, and the polarity of MR depended upon materials inserted and their film thickness.