Figure 3. Free-energy landscape.
Free-energy-like quantity versus internal energy (in meV per 5-atom cell) for (1−x)Ba(Zr0.2Ti0.8)O3−x(Ba0.7Ca0.3)TiO3 with x=0.50 (BCTZ-0.5) in yellow, and BaTiO3 (BTO) in red, at their P4mm–Amm2 transition temperatures (which are 297 and 283 K, respectively). Results correspond to the use of a 18 × 18 × 18 supercell. This free-energy-like quantity is the logarithm of the normalized canonical distribution28.