Presentation Information
[7p-N201-3]Tunable Ferroelectricity in Layered Perovskite Oxides Ln2SrSc2O7 (Ln = La, Nd)
〇(DC)YANG ZHANG1, Tatsushi Kawasaki1, Daiming Tang3, Shuki Torii2, Yi Wei1, Koji Fujita1 (1.Kyoto Univ., 2.KEK., 3.NIMS.)
Keywords:
Ferroelectricity
Hybrid improper ferroelectricity (HIF), where polarization arises from a trilinear coupling of nonpolar octahedral rotations, has attracted considerable interest in layered perovskites. In our previous work, we experimentally confirmed HIF in the Ruddlesden–Popper (RP) oxide La2SrSc2O7 and theoretically revealed the role of A-site cation (La/Sr) disorder in stabilizing its ferroelectricity. In this study, we systematically tune the A-site disorder by varying cooling contditions after high temperature sintering to control ferroelectric properties in Ln2SrSc2O7 (Ln = La, Nd). Structural and dielectric characterizations (SXRD, NPD, SHG, STEM, P–E loops) confirm that A-site disorder critically influences ferroelectric phase stability through competition between ScO6 octahedral deformation and rotation.