2017/11/17 by M. Paściak, Marek Paściak, T. R. Welberry +4 · 1 citation
Materials Science · Physics and Astronomy · #Anharmonicity #Anisotropy #Condensed matter physics #Dielectric #Displacement (psychology) #Ferroelectric and Piezoelectric Materials #Ferroelectricity #Materials science #Optics #Phase (matter) #Phonon #Photorefractive and Nonlinear Optics #Physics #Quantum mechanics #Scattering #X-ray Diffraction in Crystallography #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.120.167601
published as Phys. Rev. Lett. 120, 167601 (2018) · 5 pages, 4 figures
arxiv created 2017/11/17 · openalex created_date 2017/12/04 · openalex publication_date 2018/04/20 · arxiv updated 2018/04/25 · openalex updated_date 2026/08/05
The three-dimensional distribution of the x-ray diffuse scattering intensity of BaTiO3 has been recorded in a synchrotron experiment and simultaneously computed using molecular dynamics simulations of a shell model. Together, these have allowed the details of the disorder in paraelectric BaTiO3 to be clarified. The narrow sheets of diffuse scattering, related to the famous anisotropic longitudinal correlations of Ti ions, are shown to be caused by the overdamped anharmonic soft phonon branch. This finding demonstrates that the occurrence of narrow sheets of diffuse scattering agrees with a displacive picture of the cubic phase of this textbook ferroelectric material. The presented methodology allows one to go beyond the harmonic approximation in the analysis of phonons and phonon-related scattering.