Magnetoelectric Coupling Induced Orbital Reconstruction and Ferromagnetic Insulating State in PbZrTiO/LaSrMnO Heterostructures.

Novel phenomena at the ferromagnetic/ferroelectric interface have generated much interest. Here, a ferromagnetic insulating state with the Curie temperature about 268-286 K in PbZrTiO/LaSrMnO heterostructures is induced and modulated by varying the PbZrTiO thickness. An abnormally enlarged / ratio in LaSrMnO by strain-based coupling effect leads to orbital preferable occupancy. This orbital reconstruction modulates effective electron transfer and finally leads to a ferromagnetic insulating state. Valence change induced by charge-based coupling effect could be partially responsible for change in the Curie temperature in the strongly correlated electron system of LaSrMnO. This work provides a deeper understanding of strain effects near the ferromagnetic/ferroelectric interface, especially in a PbZrTiO/LaSrMnO heterostructure system.