Strain-based magneto-electric coupling effect induced orbital reconstruction and near room temperature ferromagnetic insulator state in PbZr_0.52Ti_0.48O₃/La_0.67Sr_0.33MnO₃ heterostructure

Multiferroic heterostructures attracts much attention due to fascinating potential applications in electric field control of magnetism and abundant physics significance. However, more and more fascinating phenomenon appearing near ferromagnetic/ferroelectric interface requires deeper investigation on this interface and the related coupling mechanism. Here, a near room temperature ferromagnetic insulator state in PbZr_0.52Ti_0.48O₃/La_0.67Sr_0.33MnO₃ heterostructures was reported by varying PbZr_0.52Ti_0.48O₃ thickness. Abnormal enlarged c/a ratio in La_0.67Sr_0.33MnO₃ by strain-based coupling effects, which lead to d_3z2-r2 orbital preferable occupancy and narrower e_g bandwidth, was regarded as the dominant reason while valence change induced by charge-based coupling effects could be limited responsible considering short screening length. This work paves a deeper understanding of strain-based coupling effects across ferromagnetic/ferroelectric interface and enrich physics content in La_1-xSr_xMnO₃ based electron strong correlated system