Exchange bias at low fields exhibited by the interface between epitaxial layers of ferromagnetic and charge‐ordered rare‐earth manganites

Epitaxial thin films of ferromagnetic La_0.7Sr_0.3MnO₃ (LSMO) and charge‐ordered, antiferromagnetic Y_0.5Ca_0.5MnO₃ (YCMO) were deposited on SrTiO₃ (100) substrates by pulsed laser deposition (PLD). The heterostructure undergoes tetragonal distortion due to strong biaxial tensile strain imposed by the substrate. The LSMO–YCMO bilayers exhibit significant exchange bias (EB) across the interface even in a very small remnant magnetic field (～5 Oe) present in the superconductor magnet. The unidirectional exchange anisotropy at the interface can be switched by reversing the polarity of the remnant magnetic field.