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

Abstract

Among six ZrO2 phases, the tetragonal ZrO2 with space group P42/nmc (D4h15, 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 P42/mnm (D4h14, 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 micro-crack, the mechanical and dynamical stabilities show the novel t-ZrO2-II is a better dielectric and structural material than t-ZrO2-I reported previously.