Tunnel magnetoresistance in La_(0.7)Ca_(0.3)MnO_(3)/PrBa_(2)Cu_(3)O_(7)/La_(0.7)Ca_(0.3)MnO_(3)

摘要

We report large tunneling magnetoresistance in La_(0.7)Ca_(0.3)MnO_(3) (8 nm)/PrBa_(2)Cu_(3)O_(7) (2.4 nm)/La_(0.7)Ca_(0.3)MnO_(3) (50 nm) junctions. The coherent growth of the cuprate on the manganite allows the deposition of ultrathin barriers which are continuous and flat over long lateral distances. Epitaxial strain causes the top layer to be a weaker ferromagnet without a significant decrease in the spin polarization.