Orbital Reconstruction Enhanced Exchange Bias in La 0.6 Sr 0.4 MnO 3 /Orthorhombic YMnO 3 Heterostructures

The exchange bias in ferromagnetic/multiferroic heterostructures is usually considered to originate from interfacial coupling. In this work, an orbital reconstruction enhanced exchange bias was discovered. As La 0.6 Sr 0.4 MnO 3 (LSMO) grown on YMnO 3 (YMO) suffers a tensile strain ( a > c ), the doubly degenerate e g orbital splits into high energy 3 z 2 − r 2 and low energy x 2 − y 2 orbitals, which makes electrons occupy the localized x 2 − y 2 orbital and leads to the formation of antiferromagnetic phase in LSMO. The orbital reconstruction induced antiferromagnetic phase enhances the exchange bias in the LSMO/YMO heterostructures, lightening an effective way for electric-field modulated magnetic moments in multiferroic magnetoelectric devices.