Abstract
We report the Pockels electro-optic properties of and orthorhombic and rhombohedral ferroelectric phases, and we compare them to the well-known rhombohedral Pockels material from density functional theory calculations using the crystal suite of programs. Specifically, three essential processes are explicitly investigated: The electronic, the ionic (or vibrational), and the piezoelectric contributions. Our calculations reveal that the ionic part coming from the low-frequency phonon modes contributes the most to the electro-optic coefficients of rhombohedral and of orthorhombic and . Additionally, the low-frequency phonon modes exhibit zero contribution to the Pockels coefficients of and rhombohedral phase.
- Received 27 September 2022
- Revised 7 December 2022
- Accepted 3 January 2023
DOI:https://doi.org/10.1103/PhysRevB.107.045140
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