Growth and properties of a noncentrosymmetric polyphosphate CsLa(PO 3 ) 4 crystal with deep-ultraviolet transparency

• Published in: CrystEngComm 2014-12, Vol.16 (45), p.10497-10504
• Main Authors: Sun, Tongqing, Shan, Pai, Chen, Hong, Liu, Xuanwen, Liu, Hongde, Chen, Shaolin, Cao, Ya'an, Kong, Yongfa, Xu, Jingjun
• Format: Article
• Language: English
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/C4CE01658K

To explore new deep-ultraviolet (deep-UV) nonlinear optical crystals, the CsLa(PO 3 ) 4 crystal with noncentrosymmetric crystallographic structure was grown by spontaneous nucleation using the flux method and slow-cooling technique. A single crystal with a size of 28 mm × 14 mm × 5 mm was easily obtained. Two perfect cleavage behaviours of the CsLa(PO 3 ) 4 crystal were found and the reason was discussed from the point of view of bond length and symmetry. The thermal stability and specific heat capacity of CsLa(PO 3 ) 4 were investigated. The CsLa(PO 3 ) 4 crystal remarkably exhibits a deep-UV cutoff edge of 167 nm, which is one of the shortest values among phosphates to date. Polycrystalline powder of CsLa(PO 3 ) 4 presents a moderate second harmonic generation (SHG) response, which is about one half of that of KH 2 PO 4 (KDP). Analysis of the dipole moments for the polyhedra and theoretical calculations by density functional theory (DFT) were performed for understanding the structure–function relationships in the CsLa(PO 3 ) 4 crystal.