Strain-tunable unconventional exchange-bias effect in epitaxial CaIrO3/LaMnO3 heterostructures.

The interfacial coupling in epitaxially grown bilayers composed of paramagnetic CaIrO 3 and ferromagnetic LaMnO 3 bilayers has been shown to give rise to an unexpected exchange bias effect. Systematic magnetic measurements ascribe this effect to the existence of an interfacial spin-cluster-like state in the bilayers. Furthermore, by tuning the epitaxial strains in the bilayers with different growth sequences, a much stronger exchange bias effect is observed in the CaIrO 3 /LaMnO 3 bilayer rather than the LaMnO 3 /CaIrO 3 bilayer, revealing the indispensable role of epitaxial strains in engineering the interfacial coupling. [ABSTRACT FROM AUTHOR]