We report the Pockels electro-optic properties of ZrO2 and HfO2 orthorhombic Pbc21 and rhombohedral R3m ferroelectric phases, and we compare them to the well-known LiNbO3 Pockels material from density functional theory calculations using the CRYSTAL suite of programs. Specifically, three essential processes are explicitly investigated: The electronic, the ionic (or vibrational), and the piezoelectric contributions. Our calculations reveal that the ionic part coming from the low frequency phonon modes contributes the most to the electro-optic coefficients of rhombohedral LiNbO3 and of orthorhombic ZrO2 and HfO2. While these low-frequency modes show zero contribution to Pockels coefficients for the rhombohedral phase of the latter compounds.

中文翻译：

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ZrO2、HfO2 和 LiNbO3 铁电相的电光特性：与密度泛函理论的综合比较研究

我们报告了 ZrO2 和 HfO2 正交 Pbc21 和菱面体 R3m 铁电相的 Pockels 电光特性，并使用 CRYSTAL 程序套件从密度泛函理论计算中将它们与著名的 LiNbO3 Pockels 材料进行了比较。具体来说，明确研究了三个基本过程：电子、离子（或振动）和压电贡献。我们的计算表明，来自低频声子模式的离子部分对菱面体 LiNbO3 和正交 ZrO2 和 HfO2 的电光系数贡献最大。虽然这些低频模式对后者化合物的菱面体相的 Pockels 系数的贡献为零。