Synthesis, Crystal Structure, and Characterization of a Noncentrosymmetric Sulfate Cs₂Ca₂(SO₄)₃

Abstract

The noncentrosymmetric structure is one prerequisite of a nonlinear optical (NLO) material. Here, a sulfate Cs2Ca2(SO4)3 with a noncentrosymmetric structure was synthesized by high‐temperature solid‐state reaction, and its crystals were grown by spontaneous crystallization. Single‐crystal X‐ray diffraction indicates that Cs2Ca2(SO4)3 features a three‐dimensional framework constituted by corner‐sharing CaO6 octahedra and SO4 tetrahedra. Optical characterizations suggest that Cs2Ca2(SO4)3 is transparent down to 200 nm and exhibits a moderate second‐order NLO response of about 0.6 × KH2PO4. Electronic band structure calculations were performed to elucidate the optical origin. Furthermore, the title compound has good thermal stability of up to about 1000 K, which is greatly higher than those of NLO sulfates reported recently. This work may shed useful light on the development of new NLO sulfates with high thermal stability.

Li2.9Cs1.1(SO4)2: An Ultraviolet Transparent Sulfate as a Nonlinear Optical Crystal

“…Figure 5 shown that the SHG response of LCSO demonstrate 0.8 × KDP (180− 250 μm). This result is comparable to other UV NLO sulfates, including (NH 4 ) 2 Na 3 Li 9 (SO 4 ) 7 (0.5 × KDP), 2 6 NH 3 SO 3 (NH 4 ) 2 SO 4 (0.8 × KDP), 60 Cs 2 Ca 2 (SO 4 ) 3 (0.6 × KDP), 61 and Li 2 SO 4 •H 2 O (0.7 × KDP). 38 Additionally, the SHG intensity increased as particle size increased, indicating that LCSO conformed to type-I phase matching.…”

Na10Zn(NO3)4(SO3S)4: a nonlinear optical crystal combining inorganic π-conjugated and non-π-conjugated heteroanion groups

“…5b). The SHG effect of 1 was superior to those of some sulphates such as Cs 2 Zn 2 (SO 4 ) 3 (0.15 × KDP), 15 Cs 2 Ca 2 (SO 4 ) 3 (0.6 × KDP), 49 K 2 Zn 3 (SO 4 )(HSO 4 ) 2 F 4 (0.3 × KDP), 50 (NH 4 ) 2 Na 3 Li 9 (SO 4 ) 7 (0.5 × KDP), 22 KTb(SO 4 ) 2 (0.3 × KDP), 51 and Li 8 NaRb 3 (SO 4 ) 6 •2H 2 O (0.3 × KDP). 52 In addition, compared to other NLO materials containing inorganic π-conjugated and non-π-conjugated groups, compound 1 exhibits comparable or even better SHG effects.…”

A lithium–scandium sulfate with second-harmonic generation response and deep-ultraviolet transparency

“…2d). 16,[35][36][37][38][39] Li(H 2 O) 2 Sc(SO 4 ) 2 also possesses a shorter deep-UV cutoff edge than most double metal sulfates, such as NaY(SO 4 ) 2 •H 2 O (200 nm) and NaCe(SO 4 ) 2 •H 2 O (504 nm). 40 The above results suggest that Li(H 2 O) 2 Sc(SO 4 ) 2 is an attractive candidate as a NLO crystal due to its deep-UV transparency, moderate SHG response, phase-matching and a large LDT.…”