The crystal and electronic structures, dynamical stabilities and thermal properties, elastic constants and mechanical stabilities, Born effective charges and dielectric constants of a novel tetragonal ZrO2 phase: First-principles calculations

Among six ZrO2 phases, the tetragonal ZrO2 with space group P4(2)/nmc (D-4h(15), No. 137) (termed as t-ZrO2-I) has the largest average dielectric constant, but its highest elastic anisotropy easily makes a stress concentration and micro-crack and thus the lower mechanical strengths. In this paper, using first-principles calculations, we explore the crystal and electronic structures, dynamical stabilities and thermal properties, elastic constants and mechanical stabilities, Born effective charges and dielectric constants of a novel tetragonal ZrO2 with space group P4(2)/mnm (D-4h(14), No. 136) (termed as t-ZrO2-II). The larger average dielectric constant, the higher yield, plastic and fracture strengths, the smaller elastic anisotropy and thus the smaller stress concentration and less microcrack, the mechanical and dynamical stabilities show the novel t-ZrO2-II is a better dielectric and structural material than t-ZrO2-I reported previously.

Automated summary

The new tetragonal ZrO2 (t-ZrO2-II) has a larger average dielectric constant, higher yield, plastic and fracture strengths, smaller elastic anisotropy leading to less stress concentration and fewer microcracks, indicating that it is a better dielectric and structural material compared to the previously reported t-ZrO2-I.