Interface Magnetization Transition Via Minority Spin Injection

The interface magnetization of n-type BaTiO3/La0.7Sr0.3MnO3 heterojunction is selectively probed by magnetic second-harmonic generation at 80 K. The injection of minority spins at the interface causes a sudden, reversible transition of the spin alignment of interfacial Mn ions from ferromagnetic to antiferromagnetic exchange coupled, while the bulk magnetization remains unchanged. We attribute the emergent interfacial antiferromagnetic interactions to weakening of the double-exchange mechanism caused by the strong Hund's rule coupling between injected minority spins and local magnetic moments. The effect is robust and may serve as a viable route for electronic and spintronic applications. Published by AIP Publishing.