Showing papers by "Jiang-Gao Mao published in 2019"
TL;DR: A new ultraviolet nonlinear optical (NLO) material, namely LiHgPO4, was synthesized by mild hydrothermal method and theoretical calculations revealed that the introduction of the Hg2+ in a highly distorted HgO6 oc-tahedral geometry is crucial to produce the strong SHG re-sponse and large birefringence.
Abstract: A new ultraviolet nonlinear optical material, namely LiHgPO4, was synthesized using the mild hydrothermal method. The structure of LiHgPO4 features novel double layers constructed by severely distorted HgO6 octahedra and PO4 tetrahedra, which are further interconnected by LiO4 tetrahedra to form a three-dimensional structure. LiHgPO4 exhibits a very strong second harmonic generation (SHG) response of 11.0 times that of KH2PO4 and a relatively large birefringence (0.068 at 1064 nm) among the reported SHG-active phosphates. Theoretical calculations revealed that the introduction of the Hg2+ in a highly distorted HgO6 octahedral geometry is crucial to produce the strong SHG response and large birefringence.
159 citations
TL;DR: It is proposed that three-site aliovalent substitution is a facile route for the discovery of good NLO materials.
Abstract: Two mixed-metal gallium iodate fluorides, namely, α- and β-Ba2 [GaF4 (IO3 )2 ](IO3 ) (1 and 2), have been designed by the aliovalent substitutions of α- and β-Ba2 [VO2 F2 (IO3 )2 ](IO3 ) (3 and 4) involving one cationic and two anionic sites. Both 1 and 2 display large second-harmonic generation responses (≈6×KH2 PO4 (KDP)), large energy band gaps (4.61 and 4.35 eV), wide transmittance ranges (≈0.27-12.5 μm), and high relevant laser-induced damage thresholds (29.7× and 28.3×AgGaS2 , respectively), which indicates that 1 and 2 are potential second-order nonlinear optical materials in the ultraviolet to mid-infrared. Our studies propose that three-site aliovalent substitution is a facile route for the discovery of good NLO materials.
95 citations
TL;DR: This work shows that the hydrothermal reaction under phosphoric acid medium facilitates the formation of rare-earth polyiodates.
Abstract: The first examples of rare-earth polyiodates, namely, REI5 O14 (RE=Y and Gd), have been prepared by hydrothermal reactions of RE2 O3 and H5 IO6 in H3 PO4 (≥85 wt % in H2 O), with extremely high yields (>95 %). They crystalize in the polar space group Cm and feature a brand-new semicircle-shaped [I5 O14 ]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×KH2 PO4 (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.
62 citations
TL;DR: A novel cesium bismuth germanate, Cs2Bi2O(Ge2O7) (CBGO), was synthesized by traditional high temperature solid state reaction and possesses a moderate birefringence, which is phase matchable and exhibits high thermal stability.
Abstract: A cesium bismuth germanate, Cs2Bi2O(Ge2O7) (CBGO), was synthesized by a traditional high-temperature solid-state reaction. Its structure features a 3D network composed of a 1D chains composed of Bi2O8 dimers that are further bridged by Ge2O7 dimers, forming tunnels of seven member rings (MRs) that are filled by the Cs+ cations. CBGO exhibits extraordinary larger second harmonic generation (SHG) response of about 13.7 times that of KDP (KH2PO4) under 1064 nm laser radiation and 1.1 times that of KTP (KTiOPO4) under 2.05 mu m laser radiation, which is the highest among all of the metal germanates reported so far. CBGO possesses a moderate birefringence (0.073 at 1064 nm) and is phase matchable. Furthermore, CBGO melts congruently and exhibits high thermal stability.
46 citations
TL;DR: An excellent SHG iodate, LiMg(IO3)3, has been obtained via the aliovalent substitution of defect-containing MIV sites with ordered Mg2+.
Abstract: An excellent second harmonic generation (SHG) material, LiMg(IO3)3 (LMIO), has been elaborately designed from Li2MIV(IO3)6 (MIV = Ti, Sn, and Ge) by aliovalent substitution of the central MIV cation followed by Wyckoff position exchange. The new structure sustains the ideal-alignment of (IO3)- groups. Importantly, LMIO exhibits an extremely strong SHG effect of roughly 24 × KH2PO4 (KDP) under 1064 nm laser radiation or 1.5 × AgGaS2 (AGS) under 2.05 μm laser radiation, which is larger than that of α-LiIO3 (18 × KDP). The replacement of MIV with Mg2+ without d-d electronic transitions induces an obviously larger band gap (4.34 eV) with a short absorption edge (285 nm). This study shows that single-site aliovalent substitution provides a new synthetic route for designing SHG materials.
40 citations
TL;DR: Preliminary results indicate that Ba4Bi2(Si8-x B4+x O29) (x = 0.09) is a new second-order nonlinear-optical crystalline material candidate.
Abstract: A new acentric metal borosilicate, namely Ba4Bi2(Si8−xB4+xO29) (x = 0.09), has been synthesized by a standard solid-state reaction. The title compound crystallizes in noncentrosymmetric (NCS) space group I2m with lattice parameters a = 11.0254(4) A and c = 10.3961(9) A. Structure refinements indicate that mixing of B atoms and Si atoms exists for a few atomic sites. In the “ideal” Ba4Bi2(Si8B4O29), BO4 or SiO4 tetrahedra are inter-connected by corner-sharing to cyclic B4O12 or Si4O12 units. These B4O12 and Si4O12 units are further interconnected via corner-sharing to an “ideal” [Si8B4O29]14− 3D network. The Ba2+ and Bi3+ act as the counter cations and are located at the cavities of the structure. Ba4Bi2(Si8−xB4+xO29) (x = 0.09) melts incongruently at a high temperature of 929 °C. Powder second-harmonic generation (SHG) measurements reveal that Ba4Bi2(Si8−xB4+xO29) (x = 0.09) is a type I phase-matching compound with a good SHG response of about 5.1 times that of KDP (KH2PO4), which is the highest among the borosilicates reported so far. The SHG source has been studied by DFT theoretical calculations. Our preliminary results indicate that Ba4Bi2(Si8−xB4+xO29) (x = 0.09) is a new second-order nonlinear-optical crystalline material candidate.
38 citations
TL;DR: A series of new acentric fluoroborophosphates have been obtained by combining BO3F or BO2F2 with a PO4 tetrahedron in this article, where the structures of the isomeric RbBPO4F and CsBPO 4F feature a three-dimensional diamond framework.
Abstract: A series of new acentric fluoroborophosphates, namely, RbBPO4F, CsBPO4F and (NH4)2BPO4F2, have been obtained by combining BO3F or BO2F2 with a PO4 tetrahedron. The structures of the isomeric RbBPO4F and CsBPO4F feature a three-dimensional diamond framework, in which a BO3F (or PO4) tetrahedron corner is shared with three PO4 (or BO3F) tetrahedra, forming 1D tunnels of eight-membered rings (MRs) along the three axial directions, which are filled with alkali cations. (NH4)2BPO4F2 exhibits a 3D supramolecular structure, in which 1D [BPO4F2]−∞ anionic chains along the a axes based on corner-sharing and alternating PO4 and BO2F2 tetrahedra are further interconnected with ammonium cations by electrostatic attractions and hydrogen bonds. RbBPO4F, CsBPO4F and (NH4)2BPO4F2 display second-harmonic generation (SHG) signals approximately 0.4, 0.6 and 0.8 times that of KH2PO4 (KDP) and exhibit short UV absorption edges (<200 nm). Measurements of thermal stability and optical properties and theoretical calculations have also been performed.
31 citations
TL;DR: Results of theoretical calculation show that the formation of I4O112- is thermodynamically much easier than I3O8- and I2O5, because of the lower reaction energy.
Abstract: Two new barium polyiodate compounds in the alkali-earth system, namely, HBa2.5(IO3)6(I2O5) (Fdd2) and HBa(IO3)(I4O11) (P1) have been obtained through hydrothermal reaction. Interestingly, the stru...
31 citations
TL;DR: It was found that the asymmetric SeO3 groups displayed the largest anisotropy, compared with the bismuth cations and the d0 -TM/Te polyhedra, which is beneficial to the birefringence.
Abstract: The first examples of bismuth fluoride selenites with d0 -TM/TeVI polyhedrons, namely, Bi4 TiO2 F4 (SeO3 )4 (1), Bi4 NbO3 F3 (SeO3 )4 (2), Bi4 TeO4 F2 (TeO3 )2 (SeO3 )2 (3), Bi2 F2 (MoO4 )(SeO3 ) (4) and Bi2 ZrO2 F2 (SeO3 )2 (5) have been successfully synthesized under hydrothermal reactions by aliovalent substitution. The five new compounds feature three different types of structures. Compounds 1-3, containing TiIV , NbV and TeVI respectively, are isostructural, exhibiting a new 3D framework composed of a 3D bismuth oxyfluoride architecture, with intersecting tunnels occupied by d0 -TM/TeVI octahedrons and selenite/tellurite groups. Interestingly, compound Bi4 TeO4 F2 (TeO3 )2 (SeO3 )2 (3) is the first structure containing SeIV and mixed-valent TeIV /TeVI cations simultaneously. Compound 4 features a new 3D structure formed by a 3D bismuth oxyfluoride network with MoO4 tetrahedrons and selenites groups imbedded in the 1D tunnels. Compound 5 displays a novel pillar-layered 3D open framework, consisting of 2D bismuth oxide layers bridged by the [ZrO2 F2 (SeO3 )2 ]6- polyanions. Theoretical calculations revealed that the five compounds displayed very strong birefringence. The birefringence values of compounds 1-3, especially, are above 0.19 at 1064 nm, which are larger than the mineral calcite. Based on the structure and property analysis, it was found that the asymmetric SeO3 groups (and TeO3 in compound 3) displayed the largest anisotropy, compared with the bismuth cations and the d0 -TM/Te polyhedra, which is beneficial to the birefringence.
24 citations
TL;DR: The first environmentally friendly defect-induced white-light emitting crystalline inorganic borate, Ba2[Sn(OH)6][B( OH)4]2, has been prepared and is the first borate-stannate without Sn-O-B linkage.
Abstract: In response to ever-increasing application requirements in lighting and displays, a tremendous emphasis is being placed on single-component white-light emission. Single-component inorganic borates doped with rare earth metal ions have shown prominent achievements in white-light emission. The first environmentally friendly defect-induced white-light emitting crystalline inorganic borate, Ba2 [Sn(OH)6 ][B(OH)4 ]2 , has been prepared. Additionally, it is the first borate-stannate without a Sn-O-B linkage. Notably, Ba2 [Sn(OH)6 ][B(OH)4 ]2 shows Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of (0.42, 0.38), an ultrahigh color rendering index (CRI) of 94.1, and an appropriate correlated color temperature (CCT) of 3083 K. Such a promising material will provide a new approach in the development of white-light emitting applications.
23 citations
TL;DR: P Powder second harmonic generation measurements disclosed that In3(SO4)(TeO3)2F3(H2O) exhibits a weak frequency-doubling efficiency about 11% of the commercial KDP, which is about 36 times that of AGS.
Abstract: Two new indium sulfate tellurites, namely, In2(SO4)(TeO3)(OH)2(H2O) and In3(SO4)(TeO3)2F3(H2O), were synthesized by hydrothermal method in a one-pot reaction. Their pure phase yields have been successfully optimized to 76% and 21%, respectively. In2(SO4)(TeO3)(OH)2(H2O) crystallized in centrosymmetric (CS) space group P21/n, while In3(SO4)(TeO3)2F3(H2O) formed a non-centrosymmetric (NCS) and chiral space group P212121. The CS compound features a 2D layered structure composed of 2D indium oxide layers decorated by sulfate tetrahedra and tellurite groups. The NCS compound displays a 3D network consisting of indium tellurite layers bridged by sulfate tetrahedra. Powder second harmonic generation measurements disclosed that In3(SO4)(TeO3)2F3(H2O) exhibits a weak frequency-doubling efficiency about 11% of the commercial KDP. Its powder laser damage threshold quantity was estimated to be 79.6 MW/cm2, which is about 36 times that of AGS. The two samples present wide optical band gaps of 4.86 and 4.10 eV, respectively, which were determined by Te, In, and O atoms based on density functional theory calculations.
TL;DR: Three new acentric Sc-based borates, K6ACaSc2(B5O10)3 (A = Li, Na, Li0.7Na0.3; space group R32), have been obtained and characterized and possess moderate second-harmonic-generation (SHG) responses.
Abstract: Three new acentric Sc-based borates, K6ACaSc2(B5O10)3 (A = Li, Na, Li0.7Na0.3; space group R32), have been obtained and characterized. They are isostructural, and all exhibit three-dimensional [Sc2(B5O10)3]9- anionic architecture composed of B5O10 clusters and ScO6 octahedra with the alkali- and alkaline-earth-metal cations occupying the cavities and keeping the charge balance. These compounds possess moderate second-harmonic-generation (SHG) responses (∼0.2×β-BaB2O4 at 532 nm and ∼0.4×KH2PO4 at 1064 nm) with phase-matching abilities and importantly display short cutoff edges below 200 nm. Furthermore, the relationship between the crystal structure and the SHG property has also been discussed based on the theoretical calculations.
TL;DR: This compound is the first metal phosphate chloride featuring infinite [PO3]∞ chains, and it displays good chemical and thermal stability, as well as a short UV cutoff edge (<200 nm) and relatively large birefringence.
Abstract: We adopted a chemical substitution strategy to design a particular anionic structure with large optical anisotropy in phosphate. Specifically, we replaced one O2– in Ba3P3O10Cl by two Cl–, leading to the formation of a new compound of BaPO3Cl (P21/c). Notably, this compound is the first metal phosphate chloride featuring infinite [PO3]∞ chains, and it displays good chemical and thermal stability, as well as a short UV cutoff edge (<200 nm) and relatively large birefringence.
TL;DR: In this article, the authors proposed a new second harmonic generation materials in Ag+-Hg2+/Bi3++-selenites systems with three new silver selenium oxides.
Abstract: Explorations of new second harmonic generation materials in Ag+-Hg2+/Bi3+-selenites systems afforded three new silver selenium oxides, namely, Ag4Hg(SeO3)2(SeO4) (1), Ag2Bi2(SeO3)3(SeO4) (2) and Ag5Bi(SeO3)4 (3). They exhibit flexible crystal chemistry. Compounds 1 and 2 are mixed valence selenium oxides containing Se(IV) and Se(VI) cations simultaneously. Compounds 1 and 3 exhibit a 3D open framework with 4-, 6- and 8-member polyhedral ring tunnels along a, b and c axes. Compound 1 crystallized in a polar space group and could display a subtle frequency doubling efficiency about 35% of the commercial KH2PO4 (KDP). UV-vis-NIR spectra reveal that compounds 1–3 are wide-band semiconductors with the optical bandgaps of 3.11, 3.65, 3.58 eV respectively. Theoretical calculations disclose that compounds 2 and 3 are indirect band gap structures and their bandgaps are determined by Ag, Bi, Se and O atoms together.
TL;DR: In this article, a new nonlinear optical material, Ba11[Al(PO4)4]-P2O7)(PO4)-3, was rationally synthesized via the hybridization of three types of anionic groups, namely [AlO4]5−, [PO4]3− and [PO7]4−, via a spontaneous nucleation method.
Abstract: A new nonlinear optical material, Ba11[Al(PO4)4](P2O7)(PO4)3, was rationally synthesized via the hybridization of three types of anionic groups, namely [AlO4]5−, [PO4]3− and [P2O7]4−, via a spontaneous nucleation method. Ba11[Al(PO4)4](P2O7)(PO4)3 was characterized with high thermal stability, deep ultraviolet transparency and moderate second-order optical nonlinearity, which were favourable for practical applications.
TL;DR: (H3O)HCs2Nb(IO3)9 gives a strong second harmonic generation (SHG) signal about 6 times that of KH2PO4 (KDP), making it a promising nonlinear optical (NLO) material.
TL;DR: In this paper, two halogenated selenites, Pb2Cd(SeO3)2X2 (X = Cl and Br), were synthesized via mild hydrothermal reactions.
Abstract: Two new halogenated selenites, namely, Pb2Cd(SeO3)2X2 (X = Cl and Br), were synthesized via mild hydrothermal reactions. The isomorphic compounds crystallized in a noncentrosymmetric (NCS) and chiral space group. Their three-dimensional (3D) structures were formed by alternating undulated [Pb2(SeO3)X]∞+ cationic layers and flattened [Cd(SeO3)X]∞− anionic layers. Thermal analyses revealed that the compounds can remain stable up to 500 °C. The SHG efficiencies of Pb2Cd(SeO3)2X2 (X = Cl and Br) are much higher than those of commercial KDP (KH2PO4), and they are phase-matchable. UV-vis-NIR diffuse reflectance spectra revealed that the two compounds exhibited wide optical band gaps. The laser damage thresholds of Pb2Cd(SeO3)2X2 (X = Cl and Br) were measured to be about 38.5 and 35.7 times higher than that of AGS (AgGaS2). Their calculated birefringences were large enough to accomplish phase matching in SHG progression. The SHG density analyses disclosed that the lone pair electrons of the SeO3 and PbOnXm units made major contributions to their nonlinear efficiencies.
TL;DR: In this paper, two new acentric borogermanates, Ca2GeB2O7 and Ca1.78Cd0.22GeB 2O7, were obtained by combining BO4 with a GeO4 tetrahedron.
Abstract: Herein, two new acentric borogermanates, namely, Ca2GeB2O7 and Ca1.78Cd0.22GeB2O7, were obtained by combining BO4 with a GeO4 tetrahedron. The structures of the isomeric Ca2GeB2O7 and Ca1.78Cd0.22GeB2O7 feature two-dimensional (2D) [GeB2O7] layers parallel to the ab plane in which a GeO4 tetrahedron corner is shared with four [B2O7] units; the divalent cations are filled in between layers. Ca2GeB2O7 and Ca1.78Cd0.22GeB2O7 display second-harmonic generation (SHG) intensity around 0.4 and 0.6 times that of KH2PO4 (KDP), respectively. Ca2GeB2O7 possesses a short UV absorption edge (about 194 nm). Thermal stability measurements show that Ca2GeB2O7 melts congruently at high temperatures, whereas Ca1.78Cd0.22GeB2O7 melts incongruently and becomes amorphous at high temperatures. Moreover, measurements of the optical properties as well as theoretical calculations of these two compounds were conducted.
TL;DR: Three new cadmium(II) tartratoborates have been successfully synthesized by the hydrothermal method and Luminescent studies suggest that they emit blue light.
Abstract: Three new cadmium(II) tartratoborates, namely, Cd5[(C4H2O6)2B]2(H2O)8·3H2O (1), K2Cd4[(C4H2O6)2B]2(H2O)2 (2), and Li0.92K1.08Cd1.5[(C4H2O6)2B](H2O)2 (3), have been successfully synthesized by the hydrothermal method. Compounds 1–3 belong to centric C2/c, acentric Pc, and the polar C2, respectively. Through based on the same hybrid borate–tartrate [(C4H2O6)2B]5– anions, they exhibit different structures. The [(C4H2O6)2B]5– anion is composed of two tartrate anions and a B(OH)4– unit. Compound 1 features a novel 3D network formed by 2D {Cd3[(C4H2O6)2B]2(H2O)2}4– anionic layers and [Cd2O10] dimers, forming tunnels of large 14-MRs which are filled by the non-coordination water molecules. Compound 2 has a characteristic 3D network based on {Cd2[(C4H2O6)2B]}− units interlinked via carboxylate groups, forming tunnels of 11-MRs, half of which stuffed with the K+ ions. Compound 3 features 2D {Cd4[(C4H2O6)4B]}3+ layers which are separated by K/Li ions. Luminescent studies suggest that they emit blue light. Compounds...