The strain effect and the ferroelectric field effect in LaMnO3+δ film/Pb(Mg1/3Nb2/3)O3–PbTiO3 single-crystal heterostructures

• Ferroelectric polarization switching induces strain and electric charge.
• Strain effect competes with charge effect.
• Magnetoelectric coupling is strain-mediated at high temperature but charge-mediated at low temperature.

The evolution of the competition and coaction between the ferroelectric field effect and the strain effect with temperature has been studied for the LaMnO3+δ film/Pb(Mg1/3Nb2/3)O3–PbTiO3 crystal heterostructure. The polarization-rotation-induced strain has a dramatic impact on the electronic transport properties at room temperature. Upon cooling, the polarization-rotation-induced interfacial charge effect competes with and finally overwhelms the strain effect, and modulates the transport and magnetic properties of the LaMnO3+δ film reversibly via the depletion or accumulation of hole carriers at interface. The identification of charge carrier-mediated electric-field-control of the electronic transport and magnetic properties would help researchers better understand the magnetoelectric coupling mechanism in manganite film/ferroelectric crystal heterostructures.