The First UV Nonlinear Optical Selenite Material: Fluorination Control in CaYF(SeO₃)₂ and Y₃F(SeO₃)₄

Abstract

It is a great challenge to develop UV nonlinear optical (NLO) material due to the demanding conditions of strong second harmonic generation (SHG) intensity and wide band gap. The first ultraviolet NLO selenite material, Y3F(SeO3)4, has been obtained by control of the fluorine content in a centrosymmetric CaYF(SeO3)2. The two new compounds represent similar 3D structures composed of 3D yttrium open frameworks strengthened by selenite groups. CaYF(SeO3)2 has a large birefringence (0.138@532 nm and 0.127@1064 nm) and a wide optical band gap (5.06 eV). The non‐centrosymmetric Y3F(SeO3)4 can exhibit strong SHG intensity (5.5×KDP@1064 nm), wide band gap (5.03 eV), short UV cut‐off edge (204 nm) and high thermal stability (690 °C). So, Y3F(SeO3)4 is a new UV NLO material with excellent comprehensive properties. Our work shows that it is an effective method to develop new UV NLO selenite material by fluorination control of the centrosymmetric compounds.

AAl(Te4O10) (A = Na, Ag) and K2Ga2(HTe6O16)(HTeO3): Three Aluminum/Gallium Tellurites with Large Birefringence and Wide Band Gap

“…1−10 Te IV cations when coordinated with O atoms can form three different basic anionic building blocks, namely, [TeO 3 ] 2− , [TeO 4 ] 4− , and [TeO 5 ] 6− , such as the tellurite groups in Ba(MoO 2 F) 2 (TeO 3 ) 2 , 11 Li 7 (TeO 3 ) 3 F, 12 Ba-(MoOF 2 )(TeO 4 ), 13 Bi 2 TeO 5 , 14 and so on. These basic anionic building blocks can be further polymerized into zerodimensional (0D) clusters, one-dimensional (1D) chains, two-dimensional (2D) layers, and even three-dimensional (3D) network structures, such as 0D clusters in Sr 4 (Te 3 O 8 )-C l 4 , 1 5 R b [ T e 2 O 4 ( O H ) 5 ] , 1 6 C s Y T e 3 O 8 , 1 7 a n d Ba 2 V 4 O 8 (Te 3 O 10 ), 18 1D chains in BaLiTe 2 O 5 Cl, 19 Y 2 (Te 4 O 10 )(SO 4 ), 20 Cd 7 Cl 8 (Te 7 O 17 ), 21 and Nd 2 (MoO 4 )-(Te 4 O 10 ), 22 2D layers in Zn 4 (Te 3 O 7 ) 2 (SO 4 ) 2 (H 2 O), 23 NdTe 2 O 5 Br, 24 Ba 3 PbTe 6 O 16 , 25 and RbNaTe 8 O 14 (OH) 6 • 8H 2 O, 26 and 3D networks in Ag 3 F 3 (TeF 6 )(TeO 2 ) 12 27 (Figure S1). Additionally, when Te IV is coordinated with F and O atoms simultaneously, new basic building blocks TeO 2 F, TeO 2 F 2 , and TeF 3 will be formed, such as the fluorotellurite groups in AgTeO 2 F, 27 Bi 3 F(TeO 3 )(TeO 2 F 2 ) 3 , 28a HgTeO 2 F-(OH), 29 and BaF 2 TeF 2 (OH) 2 .…”