TY - JOUR

T1 - Lattice dynamics and the ferroelectric phase transition

AU - Smirnov, M.

AU - Hlinka, J.

PY - 2000

Y1 - 2000

N2 - This paper presents a quasiharmonic model for the lattice dynamics of the (Formula presented) crystal. The model, constructed as a combination of the valence force field and the polarizable ion model with a majority of potential parameters fixed by auxiliary Hartree-Fock calculations, enables us to calculate vibrational spectra for both the paraelectric and the ferroelectric structure. The calculated eigenvector of the lowest frequency optic mode corresponds to the order parameter of the ferroelectric phase transition and can be identified with the symmetry-breaking soft mode. Interpretation of the obtained results and their comparison with available experimental data is provided.

AB - This paper presents a quasiharmonic model for the lattice dynamics of the (Formula presented) crystal. The model, constructed as a combination of the valence force field and the polarizable ion model with a majority of potential parameters fixed by auxiliary Hartree-Fock calculations, enables us to calculate vibrational spectra for both the paraelectric and the ferroelectric structure. The calculated eigenvector of the lowest frequency optic mode corresponds to the order parameter of the ferroelectric phase transition and can be identified with the symmetry-breaking soft mode. Interpretation of the obtained results and their comparison with available experimental data is provided.

UR - http://www.scopus.com/inward/record.url?scp=0001029099&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.61.15051

DO - 10.1103/PhysRevB.61.15051

M3 - Article

AN - SCOPUS:0001029099

VL - 61

SP - 15051

EP - 15060

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 1098-0121

IS - 22

ER -