Giant negative magnetoresistance in an organic nanocrystal: site-selective device fabrication by nanoscale electrocrystallization

Herein, we report the fabrication of an organic spintronic device by a one-pot process called nanoscale electrocrystallization, that allows for the site-selective growth of organic nanocrystals on a substrate between two electrodes. Axially substituted iron phthalocyanine was used to constitute the nanocrystals that exhibited a strong correlation between the localized spin and conduction electrons. In addition, the nanocrystals exhibited a negative giant magnetoresistance ([R(B) − R(0)]/R(0)) of around −56%. Moreover, the spintronic device exhibited an angular dependence of its negative giant magnetoresistance, which confirmed the highly oriented growth of the nanocrystals by the nanoscale electrocrystallization method. In summary, our method enables the easy fabrication of organic spintronic devices based on such spin interactions.