1. Novel antimony phosphates with enlarged birefringence induced by lone pair cations.
- Author
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Hu, Mei, Wang, Jialong, Tuerhong, Nuerbiye, Zhang, Zhiyuan, Jing, Qun, Chen, Zhaohui, Yang, Yonglei, and Lee, Ming-Hsien
- Subjects
BIREFRINGENCE ,ANTIMONY ,BAND gaps ,ELECTRON pairs ,CATIONS - Abstract
Phosphates, whose obvious disadvantage is the relatively small birefringence, can be overcome by the introduction of post-transition metal cations containing stereochemically active lone-pair electrons. In this paper, two new compounds were successfully explored in the A–Sb–P–O system, i.e. Cs
2 Sb3 O(PO4 )3 (CsSbPO) and (NH4 )2 Sb4 O2 (H2 O)(PO4 )2 [PO3 (OH)]2 (NH4 SbPOH). Transmission spectra show that CsSbPO has a surprising transmission range with a UV cutoff edge of 213 nm. First-principles calculations show that both compounds have a wide band gap (5.02 eV for CsSbPO and 5.30 eV for NH4 SbPOH) and enlarged birefringence (Δn = 0.034@1064 nm for CsSbPO and Δn = 0.045@1064 nm for NH4 SbPOH). The results of real-space atom-cutting investigations show that the distorted [SbOx ] polyhedra originating from the asymmetric lone pair electrons give the main contribution to the total birefringence and overcome the disadvantage of small birefringence of phosphates but maintain wide transition windows. [ABSTRACT FROM AUTHOR]- Published
- 2024
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