Emergence of Quasi Two-Dimensional Electronic States at the Interface of LSMO/STO via Lattice Mismatch-Induced Strains

A two-dimensional interfacial electronic phase often emerges at the interface between different oxide layers, which may display remarkably distinct properties from its bulk phases. The mechanism of evolution of such an additional phase at the interface and its properties, however, are not fully understood yet. Herein, we detect an additional structural and magnetic phase and so-called quasi two-dimensional electronic states of La0.7Sr0.3MnO3 (LSMO) that interface with SrTiO3 (STO), while LSMO interfaced with a [Pb(Mg1/3Nb2/3)O3]0.7-[PbTiO3]0.3 (PMN-PT) substrate shows a single phase. We find that the additional phase exhibits a lower Curie temperature, a larger effective saturation magnetization, and a larger Gilbert damping coefficient than its bulk counterpart. We discuss that the lattice mismatch-induced strain plays an important role in the formation of the additional state. These results will give an insight into designing full-oxide electronics, including 2D spintronics.