Sensitive electric field control of first-order phase transition in epitaxial multiferroic heterostructures

Strongly correlated electron materials that exhibit rich phase transition and multiple phase separation have shown many fascinating properties. Using these properties in the electronic device will require the ability to control their phase transition and phase separation behaviours. In this work, we report a sensitive electric field control of first-order phase transition in epitaxial (011)-Nd_0.5Sr_0.5MnO₃/0.71Pb(Mg_1/3Nb_2/3)O₃–0.29PbTiO₃ (PMN-PT) heterostructure. The pristine film shows phase separation character with the penetration of the ferromagnetic metallic phase into the charge and orbital ordered antiferromagnetic insulating phase, and this was revealed by the XMCD and XLD investigation. The (011)-oriented PMN-PT piezoelectric single crystal adopted can exert anisotropic in-plane tensile strains on the epitaxial Nd_0.5Sr_0.5MnO₃ film when applying the electric field. The coaction of the electric field-induced strain and polarization effects of the PMN-PT piezoelectrics enable the efficient manipulation of orbital ordering and the coupled electronic and magnetic phase transitions. Accordingly, a small +1.6 kV cm⁻¹ electric field can recover the first-order metal-insulator transition which was inhibited in the pristine heterostructure, increase the transition temperature by 56 K and the maximum resistance change reaches 7033%. Furthermore, the electric field demonstrated non-volatile control of magnetization, and the magnetoelectric coefficient reaches 1.89 × 10⁻⁷ s m⁻¹ at 200 K. This work indicates that choosing the piezoelectric substrate with appropriate electric-field-induced strain opens a route to designing functional electronic devices where the tunable macroscopic properties derive from strongly interacting degrees of freedom present in the manganite.