An orbital strategy for regulating the Jahn–Teller effect

<jats:title>ABSTRACT</jats:title> <jats:p>The Jahn–Teller effect (JTE) arising from lattice–electron coupling is a fascinating phenomenon that profoundly affects important physical properties in a number of transition-metal compounds. Controlling JT distortions and their corresponding electronic structures is highly desirable to tailor the functionalities of materials. Here, we propose a local coordinate strategy to regulate the JTE through quantifying occupancy in the ${{d}_{{{z}^2}}}$ and ${{d}_{{{x}^2} - {{y}^2}}}$ orbitals of Mn and scrutinizing the symmetries of the ligand oxygen atoms in MnO6 octahedra in LiMn2O4 and Li0.5Mn2O4. The effectiveness of such a strategy has been demonstrated by constructing P2-type NaLixMn1–xO2 oxides with different Li/Mn ordering schemes. In addition, this strategy is also tenable for most 3d transition-metal compounds in spinel and perovskite frameworks, indicating the universality of local coordinate strategy and the tunability of the lattice–orbital coupling in transition-metal oxides. This work demonstrates a useful strategy to regulate JT distortion and provides useful guidelines for future design of functional materials with specific physical properties.</jats:p>. Authors: Shang, Tongtong [State Key Laboratory of New Ceramics and Fine Processing, National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084 , China; Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China]; Gao, Ang [State Key Laboratory of New Ceramics and Fine Processing, National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084 , China; Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China]; Xiao, Dongdong [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China; Songshan Lake Materials Laboratory , Dongguan 523808 , China]; Zhang, Qinghua [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China]; Rong, Xiaohui [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China]. DOE Contract: SC0012704. Subjects: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Jahn–Teller effect; local coordinate strategy; orbital degenerate; quantitative convergent-beam electron diffraction; transition-metal oxide