Electron Energy-Loss Spectroscopy and the Electronic Structure of ABO3 Ferroelectrics: First Principle Calculations

TL;DR

This study combines first-principles calculations and experimental EELS to analyze how the electronic structure of ABO3 ferroelectrics evolves across different crystal symmetries, highlighting the role of BO6 octahedra.

Contribution

It provides a detailed comparison of theoretical and experimental spectra, revealing electronic fingerprints for each phase and demonstrating the influence of BO6 octahedra on energy spectra.

Findings

Electronic spectra vary with crystal symmetry changes.

Theoretical and experimental spectra show good agreement.

Anomalous plasmon behavior observed near phase transition.

Abstract

The electronic structures of ABO3 ferroelectrics are calculated within the density functional theory, and their evolution is analyzed as the crystal-field symmetry changes from cubic to rhombohedral via tetragonal phases. Electronic structure fingerprints that characterize each phase from their electronic spectra are identified. We carried out electron-energy loss spectroscopy experiments by using synchrotron radiation and compared these results to the theoretical spectra calculated within DFT-LDA. The dominant role of the BO6 octahedra in the formation of the energy spectra of ABO3 compounds was demonstrated. Anomalous behavior of plasmons in ferroelectrics was exhibited by the function representing the characteristic energy loss in the region of phase transition.