Characteristics of Low‐Energy Phases of Hafnia and Zirconia from Density Functional Theory Calculations

A systematic simulation study of low-energy phases HfO2 and ZrO2, including 24-atomic cells derived from 180° interphases, leads to a new monoclinic Pc phase (mIII) with angle β = 85 ∘ polarization 0.3 C m−2. This opens up transition path toward the P2 1 /c (m) starting tetragonal P4 2 /nmc (t), comparable lower-energy barriers, where high-symmetric show largest temperature dependence. The phase, cubic (c) F m 3 ¯ less investigated (cII) P 4 are favored.