Visualization of polarization domains in ferroelectric materials

Abstract

Due to their special electrostatic properties, ferroelectrics allow for a variety of applications. The goal of this project is to use the data provided by the SciVis Contest 2012 to gain insight into the development of domains and phase transitions in ferroelectric materials. The data provided contains atom types and the atom positions, but no electrostatic dipoles. Thus, a suitable approximation has to be found. The strongest indicator for the polarization in the tetragonal phase of barium titanate is the displacement of the titanium atom in the cell center. Several methods of approximating the polarization based on the displacement of the titanium atom relative to the cell center are tested. In this project, domains are defined as clusters of vectors exhibiting a similar orientation. One way of measuring the local change of orientation of the vector field is to take the curl magnitude of the normalized vector field into account. The pervoskite structure of the lattice as well as the movement of atoms are visualized using glyph based representations. This highlights the deformation of the material, which is caused by both the temperature and the phase transition. Domains are then visualized using a combination of arrow glyphs and isosurfaces based on different scalar fields.