Local-electrostatics-induced oxygen octahedral distortion in perovskite oxides and insight into the structure of Ruddlesden–Popper phases

• DOI: 10.1038/s41467-021-25889-6
• Publication Date: 2021-09-20T10:02:53Z
• Authors: Youngjae Hong; Pilgyu Byeon; Jumi Bak; Yoon Heo; Hye-Sung Kim; Hyung Bin Bae; Sung-Yoon Chung
• Keywords: Lanio; Tetragonal crystal system

Abstract As the physical properties of ABX 3 perovskite-based oxides strongly depend on geometry oxygen octahedra containing transition-metal cations, precise identification distortion, tilt, and rotation is an essential step toward understanding structure–property correlation. Here we discover important electrostatic origin responsible for remarkable Jahn–Teller-type tetragonal distortion during atomic-level direct observation two-dimensional [AX] interleaved shear faults in five different perovskite-type materials, SrTiO , BaCeO LaCoO LaNiO CsPbBr . When sublayer has a net charge, example [LaO] + substantial elongation at fault plane observed this screens strong repulsion between consecutive layers. Moreover, our findings induced by local charge are identified to be general structural feature lanthanide-based A n 1 B X -type Ruddlesden–Popper (RP) with charged [LnO] (Ln = La, Pr, Nd, Eu, Gd) sublayers, among more than 80 RP halides high symmetry. The present study thus demonstrates that uneven electrostatics crucial factor significantly affecting crystal structure complex oxides.