1999/02/19 by A. V. Postnikov, Postnikov, A. V., V. Caciuc +5
Engineering · Physics and Astronomy · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Optical and Acousto-Optic Technologies #Photonic and Optical Devices #Photorefractive and Nonlinear Optics #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.cond-mat/9902274
presented at the '99 Williamsburg Conference on Ferroelectrics. 8 pages with 2 embedded postscript figures, uses elsart.cls
arxiv created 1999/02/19 · openalex publication_date 1999/02/19 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The equilibrium ground-state structure of LiNbO3 in the paraelectric and ferroelectric phases is fully optimized in a first-principles calculation using the full-potential linearized augmented plane wave method. The equilibrium volume, c/a ratio and all (four, in the ferroelectric phase) internal parameters are found to be in good agreement with the experimental data. Frozen phonon calculations are performed for TO-Gamma phonons corresponding to the A1 and A2 irreducible representations of the R3c space group in the ferroelectric phase. The comparison with available experimental frequencies for the A1 modes is satisfactory (including the 6Li isotope effect), and the displacement patterns are unambiguously attributed. For the (Raman inactive) A2 modes, phonon frequencies and eigenvectors are predicted.