Local cation ordering in compositionally complex Ruddlesden–Popper n = 1 oxides
Bo Jiang,
Krishna Chaitanya Pitike,
De-Ye Lin,
Stephen C. Purdy,
Xin Wang,
Yafan Zhao,
Yuanpeng Zhang,
Peter Metz,
Antonio Macias,
Harry M. Meyer III,
Albina Y. Borisevich,
Jiaqiang Yan,
Valentino R. Cooper,
Craig A. Bridges,
Katharine Page
Affiliations
Bo Jiang
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
Krishna Chaitanya Pitike
Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
De-Ye Lin
Institute of Applied Physics and Computational Mathematics, Huayuan Road 6, Beijing 100088, China and CAEP Software Center for High Performance Numercial Simulation, Huayuan Road 6, Beijing 100088, China
Stephen C. Purdy
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
Xin Wang
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
Yafan Zhao
Institute of Applied Physics and Computational Mathematics, Huayuan Road 6, Beijing 100088, China and CAEP Software Center for High Performance Numercial Simulation, Huayuan Road 6, Beijing 100088, China
Yuanpeng Zhang
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
Peter Metz
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
Antonio Macias
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
Harry M. Meyer III
Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
Albina Y. Borisevich
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
Jiaqiang Yan
Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
Valentino R. Cooper
Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
Craig A. Bridges
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
Katharine Page
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
The Ruddlesden–Popper (RP) layered perovskite structure is of great interest due to its inherent tunability, and the emergence and growth of the compositionally complex oxide (CCO) concept endows the RP family with further possibilities. Here, a comprehensive assessment of thermodynamic stabilization, local order/disorder, and lattice distortion was performed in the first two reported examples of lanthanum-deficient Lan+1BnO3n+1 (n = 1, B = Mg, Co, Ni, Cu, Zn) obtained via various processing conditions. Chemical short-range order (CSRO) at the B-site and the controllable excess interstitial oxygen (δ) in RP-CCOs are uncovered by neutron pair distribution function analysis. Reverse Monte Carlo analysis of the data, Metropolis Monte Carlo simulations, and extended x-ray absorption fine structure analysis implies a modest degree of magnetic element segregation on the local scale. Further, ab initio molecular dynamics simulations results obtained from special quasirandom structure disagree with experimentally observed CSRO but confirm Jahn–Teller distortion of CuO6 octahedra. These findings highlight potential opportunities to control local order/disorder and excess interstitial oxygen in layered RP-CCOs and demonstrate a high degree of freedom for tailoring application-specific properties. They also suggest a need for expansion of theoretical and data modeling approaches in order to meet the innate challenges of CCO and related high-entropy phases.
