Abstract

The homologous series of MF₂ (M = Ca²⁺, Sr²⁺, Ba²⁺, Cd²⁺, Pb²⁺, Sm²⁺, Eu²⁺, Yb²⁺, Ra²⁺, and Hg²⁺) crystals having the fluorite structure (CaF₂, space group \(Fm\bar {3}m,\)Z = 4) holds an important place in fluoride materials science. A correlation between the enthalpy of anti-Frenkel defect formation (H_f) and the enthalpy of melting (H_m) was elucidated for CaF₂, SrF₂, BaF₂, and PbF₂ based on the most reliable experimental data set: H_f (kJ/mol) = 8.6H_m (kJ/mol) or H_f (eV) = 0.089H_m (kJ/mol). Experimentally determined H_m values were used to calculate the enthalpies of defect formation H_f = 2.0 and 2.6 eV for CdF₂ and EuF₂ crystals, respectively. The correlation is prognostic for the whole series of homologous MF₂ fluorite crystals and for SrCl₂.

中文翻译：

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MF 2同源萤石晶体的熔化焓与反弗伦克缺陷形成焓的相关性

摘要

MF ₂（M = Ca ₂ ⁺，Sr 2 ⁺，Ba 2 ⁺，Cd 2 ⁺，Pb 2 ⁺，Sm 2 ⁺，Eu 2 ⁺，Yb 2 ⁺，Ra ²⁺和Hg ²⁺）的同源序列具有萤石结构（CaF ₂，空间群\（Fm \ bar {3} m，\）Z = 4）的晶体在氟化物材料科学中占有重要地位。阐明了CaF ₂，SrF ₂的抗Frenkel缺陷形成焓（H _f）与熔化焓（H _m）的相关性。，BaF ₂和PbF ₂基于最可靠的实验数据集：H _f（kJ / mol）= 8.6 H _m（kJ / mol）或H _f（eV）= 0.089 H _m（kJ / mol）。实验确定的H _m值分别用于计算CdF ₂和EuF ₂晶体的缺陷形成焓H _f = 2.0和2.6 eV 。该相关性对于整个系列的同源MF ₂萤石晶体和SrCl ₂是预后的。