REI₅O₁₄ (RE=Y and Gd): Promising SHG Materials Featuring the Semicircle‐Shaped I₅O₁₄³⁻ Polyiodate Anion

Abstract

The first examples of rare‐earth polyiodates, namely, REI5O14 (RE=Y and Gd), have been prepared by hydrothermal reactions of RE2O3 and H5IO6 in H3PO4 (≥85 wt % in H2O), with extremely high yields (>95 %). They crystalize in the polar space group Cm and feature a brand‐new semicircle‐shaped [I5O14]3− pentameric polyiodate anion composed of two IO3 and three IO4 polyhedra. Remarkably, both compounds exhibit very large second‐harmonic generation (SHG) signals (14× and 15×KH2PO4 (KDP) upon 1064 nm laser radiation for Y and Gd compounds, respectively). Our work shows that the hydrothermal reaction in a phosphoric acid medium facilitates the formation of rare‐earth polyiodates.

[GaF(H2O)][IO3F]: a promising NLO material obtained by anisotropic polycation substitution

“…and SALP-involving metal cations (Pb 2+ and Bi 3+ , etc.) can easily induce non-centrosymmetric (NCS) structures and large SHG responses, [28][29][30][31][32][33][34][35][36] such as BiOIO 3 (12.5 Â KDP). 37 Nevertheless, the adoption of d 0 -TM/SALP-involving metal cations would inevitably narrow the band gap due to the d-d/s-p electronic transition, and further reduce the LDT of the materials.…”

(NH4)Bi2(IO3)2F5: An Unusual Ammonium‐Containing Metal Iodate Fluoride Showing Strong Second Harmonic Generation Response and Thermochromic Behavior

“…To date, various strategies have been implemented for the design and synthesis of new iodate NLO crystals. As a result, a series of excellent iodate SHG crystals have been reported, including AMoO 3 (IO 3 ) (A=Rb, Cs), BaNbO(IO 3 ) 5 , NaI 3 O 8 , A 2 Ti(IO 3 ) 6 (A=Li, Na), (NH 4 )[MoO 3 (IO 3 )], ReI 5 O 14 (Re=Y and Gd), BiO(IO 3 ), and Bi 2 (IO 4 )(IO 3 ) 3 . Recently, fluorine‐containing iodates, such as Bi(IO 3 )F 2 , Bi 3 OF 3 (IO 3 ) 4 , ABi 2 (IO 3 ) 2 F 5 (A=K, Rb, Cs), α‐ and β‐Ba[VFO 2 (IO 3 ) 2 ], α‐ and β‐Ba 2 [VO 2 F 2 (IO 3 ) 2 ]IO 3 , α‐ and β‐Ba 2 [GaF 4 (IO 3 ) 2 ](IO 3 ), RbIO 2 F 2 , CsIO 2 F 2 , and Ce(IO 3 ) 2 F 2 ⋅H 2 O, have been demonstrated to be new types of promising NLO iodate crystals.…”

LiMII(IO3)3 (MII=Zn and Cd): Two Promising Nonlinear Optical Crystals Derived from a Tunable Structure Model of α‐LiIO3

“…Powder SHG measurements under 1064 nm and 2.05 μm laser irradiation reveal that LiZn(IO 3 ) 3 and LiCd(IO 3 ) 3 exhibit large phase‐matching SHG response in the particle size range of 150–200 mm, which is about 14× and 12×KDP at 1064 nm, and 1.1×and 1.0×KTP at 2.05 μm, respectively (Figure ). The response are larger than that of α‐LiIO 3 (≈300×α‐SiO 2 , or ≈8×KDP) and some metal iodates such as NH 4 [MoO 3 (IO 3 )] (≈8.5×KDP), α and β‐Ba 2 [VO 2 F 2 (IO 3 ) 2 ]IO 3 (≈9×KDP), comparable to A 2 M IV (IO 3 ) 6 (A=Li, Na; M IV =Ti, Sn, Ge) (400–600×α‐SiO 2 ) and other excellent metal iodates, including BiO(IO 3 ) (≈12.5×KDP), KBi 2 (IO 3 ) 2 F 5 (≈12×KDP), Bi(IO 3 )F 2 (11.5×KDP), REI 5 O 14 (RE=Y and Gd) (≈14× and 15×KDP), etc.…”