Interface-induced transition from a cluster glass state to a spin glass state in LaMnO3/BiFeO3 heterostructures

Many novel physical phenomena at the oxide heterointerfaces are expected due to the strong interfacial coupling of spin, orbit, charge and lattice degrees of freedom. Here we report a new interface phenomenon that is the interface-induced transition from a cluster glass state to a spin glass state in LaMnO3/BiFeO3 (LMO/BFO) heterostructures. The charge transfer from Mn ions to Fe ions described as Fe3+ + Mn3+ → Fe2+ + Mn4+ occurs at the interface region of LMO/BFO heterostructures; the LMO layer of a LMO/BFO heterostructure undergoes the out-of-plane tensile strain state, in contrast to the out-of-plane compressive strain state in the LMO films. The interface-induced transition from a cluster glass state to a spin glass state in LMO/BFO heterostructures can be attributed to the combined effects of interfacial charge transfer and strain effect. Our results demonstrate that the low temperature glassy magnetic state of manganites can be effectively manipulated through heterointerfaces.