中国科学院新疆理化技术研究所潘世烈团队建立了一种揭示紫外双折射材料α‐SnF2具有大的双折射率和晶体易于生长的原因的模型。 该研究结果于2020年11月10日发表在《德国应用化学》。

简单二元氟化物α-SnF2是一种优良的双折射材料，其双折射率为0.177在546nm，是MgF2的14倍。此外，与YVO4和TiO2相比，它具有较短的紫外截止边和晶体较易在室温下生长的特性。

该文建立了一种新的理论计算模型，根据立体化学活性孤对(SCALP) 的强度和排列方式分析了其对双折射（SCB）的贡献，结果表明，α-SnF2的大双折射主要得益于对齐良好的[SnF5]多面体具有强的SCALP。

该文对α-SnF2双折射晶体的研究为今后寻找优良的双折射材料指明了方向。

附：英文原文

Title: α‐SnF2: A UV Birefringent Material with Large Birefringence and Easy Crystal Growth

Author: Jingyu Guo, Abudukadi Tudi, Shujuan Han, Zhihua Yang, Shilie Pan

Issue&Volume: 10 November 2020

Abstract: Simple binary fluoride α‐SnF  2  is shown to be an excellent birefringent material with outstanding birefringence (0.177 at 546 nm), 14 times larger than that of MgF  2  . Furthermore, it exhibits a shorter UV cutoff edge and easy crystal growth at ambient temperature compared to YVO  4  and TiO  2  . A novel theoretical calculation mode was established to analyze the stereochemical activity lone pair (SCALP) contribution to birefringence (SCB) based on the SCALP’s strength and arrangement, and it can be found that the large birefringence of α‐SnF  2  mainly benefits from well‐aligned [SnF  5  ] polyhedra with the strong SCALP. The exploration of α‐SnF  2  birefringent crystal points out the direction of the future search for excellent birefringent materials.

DOI: 10.1002/anie.202014279

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202014279