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A new thio-germanium sulfide Li2Ga2GeS6 has been synthesized for the first time and its structure was found to be isomorphous with AgGaGeS4, which is well-known as a promising infrared NLO material...

Bi2Cu5B4O14 crystallizes in the noncentrosymmetric triclinic space group P1 (No. 1) with cell parameters a=10.1381(11) A, b=9.3917(11) A, c=3.4566(4) A, α=105.570(2)°, β=92.275(2)°, γ=107.783(2)°, Z=1 and R1=0.0401 and wR2=0.0980. It is a layered structure that is built up from sheets of rectangular CuO4 and trigonal BO3 groups. The sheets are connected by infinite chains of edge shared BiO6 polyhedra that intersect the bc plane at an angle slightly greater than 90°. The second-harmonic generation efficiency of Bi2Cu5B4O14, using 1064 nm radiation, is about one half times that of KH2PO4.

Complicated structures where oxygen and fluorine are found together in one framework, where deviations from Pauling's second crystal rule (PSCR) are expected, often result in structures with important physical properties. The [NbOF5]2- anion and therefore all the individual Nb-O and Nb-F bonds are ordered in noncentrosymmetric KNaNbOF5 and centrosymmetric CsNaNbOF5. The Na/K- and Na/Cs-O/F interactions in these phases, in particular the expected deviations from PSCR and the bond valence model, reveal the essential role of the small potassium cations in the acentric packing of the [NbOF5]2- anion. KNaNbOF5 crystallizes in the orthorhombic and polar space group Pna21 (No. 33) with lattice constants a = 11.8653(11) A, b = 5.8826(6) A, c = 8.1258(8) A, and Z = 4, while CsNaNbOF5 crystallizes in the orthorhombic space group Pbcn (No. 60) with lattice constants a = 8.3155(7), b = 13.3176(11), c = 11.1314(9), and Z = 8.

Two new noncentrosymmetric (NCS) polar quaternary oxides, TlMVO5 (M = Se4+ or Te4+), have been synthesized by hydrothermal techniques using Tl2CO3, SeO2 (TeO2), and V2O5 as reagents. The structures were determined by single-crystal X-ray diffraction (TlSeVO5, orthorhombic, space group Pna21 (No. 33) with a = 7.1639(15) A, b = 8.6630(19) A, c = 7.8946(17) A, V = 489.95(18) A3, and Z = 4; TlTeVO5, orthorhombic, space group Pna21 (No. 33) with a = 7.319(3) A, b = 8.749(4) A, c = 7.868(3) A, V = 503.8(4) A3, Z = 4). The materials exhibit NCS and polar three-dimensional structures consisting of chains of corner shared VO6 octahedra connected by SeO3 (TeO4) and TlO8 polyhedra. The V5+, Se4+ (Te4+), and Tl+ cations are in asymmetric coordination environments attributable to second-order Jahn−Teller (SOJT) effects. The V5+ cations undergo intra-octahedral distortions toward an edge (local C2 direction), whereas the Se4+ (Te4+) and Tl+ cations are in distorted coordination environments attributable to their lone-p...

A new polymorph of CuMoO4, e-CuMoO4, has been synthesized and characterized. The material exhibits a three-dimensional structure with tetramers of edge-shared Cu2+O5 square pyramids that link to the Mo6+O4 tetrahedra. Magnetic susceptibility measurements indicate that the material orders magnetically, with a ferromagnetic component below 10 K.

Gram-scale quantities of Eu2Ti2O7 with a [110] layered perovskite structure have been synthesized at ambient pressure by thermally oxidizing (750−900 °C) perovskite-type EuTiO3. Eu2Ti2O7 is type 1 phase matchable and shows a SHG efficiency of 80 × α-SiO2.

The title compound is prepared by solid state reaction of BaCO3, Fe2O3, and CaCO3 (Ar, 1250 °C, 80 h).

The syntheses and characterization of the acentric, B-cation ordered phase Ba4CaFe3O9.5 and a topotactically oxidized product Ba4CaFe3O10.7 are reported. Utilizing electron diffraction and neutron powder diffraction data, cation ordered structures based on a cubic perovskite lattice were refined for Ba 4CaFe3O9.5 (space group I212 121, a = 8.234(1) Å, b = 8.213(1) Å, c = 34.622(7) Å) and Ba4CaFe3O10.7 (space group I4̄2d a = 8.1821(4) Å, c = 32.3105(19) Å) The two Ba 4CaFe3O12-x phases exhibit complex structures in which Ca2+ and Fe3+ are ordered over the B-sites of the cubic perovskite lattice. This order results in the loss of structural inversion symmetry, thus the resulting cation ordered Ba4CaFe 3O12-x phases are both magnetic and acentric making them good candidates for multiferroic behavior. Further structural analysis reveals the complex cation order is induced through a combination of factors: the different coordination preferences of Ca2+ and Fe3+, anion vacancy ordering, and the need to minimize lattice strain. The general applicability of this synthetic strategy for the preparation of cation ordered materials is discussed. © 2010 American Chemical Society.

A new thio-germanium sulfide Li2Ga2GeS6 has been synthesized for the first time and its structure was found to be isomorphous with AgGaGeS4, which is well-known as a promising infrared NLO material...

Bi2Cu5B4O14 crystallizes in the noncentrosymmetric triclinic space group P1 (No. 1) with cell parameters a=10.1381(11) A, b=9.3917(11) A, c=3.4566(4) A, α=105.570(2)°, β=92.275(2)°, γ=107.783(2)°, Z=1 and R1=0.0401 and wR2=0.0980. It is a layered structure that is built up from sheets of rectangular CuO4 and trigonal BO3 groups. The sheets are connected by infinite chains of edge shared BiO6 polyhedra that intersect the bc plane at an angle slightly greater than 90°. The second-harmonic generation efficiency of Bi2Cu5B4O14, using 1064 nm radiation, is about one half times that of KH2PO4.

A new polymorph of CuMoO4, e-CuMoO4, has been synthesized and characterized. The material exhibits a three-dimensional structure with tetramers of edge-shared Cu2+O5 square pyramids that link to the Mo6+O4 tetrahedra. Magnetic susceptibility measurements indicate that the material orders magnetically, with a ferromagnetic component below 10 K.

Complicated structures where oxygen and fluorine are found together in one framework, where deviations from Pauling's second crystal rule (PSCR) are expected, often result in structures with important physical properties. The [NbOF5]2- anion and therefore all the individual Nb-O and Nb-F bonds are ordered in noncentrosymmetric KNaNbOF5 and centrosymmetric CsNaNbOF5. The Na/K- and Na/Cs-O/F interactions in these phases, in particular the expected deviations from PSCR and the bond valence model, reveal the essential role of the small potassium cations in the acentric packing of the [NbOF5]2- anion. KNaNbOF5 crystallizes in the orthorhombic and polar space group Pna21 (No. 33) with lattice constants a = 11.8653(11) A, b = 5.8826(6) A, c = 8.1258(8) A, and Z = 4, while CsNaNbOF5 crystallizes in the orthorhombic space group Pbcn (No. 60) with lattice constants a = 8.3155(7), b = 13.3176(11), c = 11.1314(9), and Z = 8.

A new polar ammonium tungsten tellurite, (NH4)2Te2WO8, has been synthesized and structurally characterized. The material was synthesized hydrothermally, using NH4OH, WO3, and TeO2 as reagents, and structurally characterized by single-crystal X-ray diffraction. (NH4)2Te2WO8 crystallizes in the noncentrosymmetric (NCS) polar monoclinic space group P21 (No. 4) with a = 6.9716(9) A, b = 7.0279(9) A, c = 9.4593(13) A, and β = 99.188(2)°. The material exhibits a two-dimensional structure consisting of WO6 octahedra connected to TeO4 polyhedra. Both the W6+ and the Te4+ cations are in asymmetric coordination environments attributable to second-order Jahn−Teller (SOJT) effects. (NH4)2Te2WO8 is NCS; thus second-harmonic generation (SHG) measurements were performed. SHG experiments, using 1064 nm radiation, revealed an efficiency of approximately 250 × α-SiO2. As (NH4)2Te2WO8 is also polar, ferroelectric and pyroelectric measurements were performed. A ferroelectric hysteresis loop (polarization vs electric field) w...

Two new noncentrosymmetric (NCS) polar quaternary oxides, TlMVO5 (M = Se4+ or Te4+), have been synthesized by hydrothermal techniques using Tl2CO3, SeO2 (TeO2), and V2O5 as reagents. The structures were determined by single-crystal X-ray diffraction (TlSeVO5, orthorhombic, space group Pna21 (No. 33) with a = 7.1639(15) A, b = 8.6630(19) A, c = 7.8946(17) A, V = 489.95(18) A3, and Z = 4; TlTeVO5, orthorhombic, space group Pna21 (No. 33) with a = 7.319(3) A, b = 8.749(4) A, c = 7.868(3) A, V = 503.8(4) A3, Z = 4). The materials exhibit NCS and polar three-dimensional structures consisting of chains of corner shared VO6 octahedra connected by SeO3 (TeO4) and TlO8 polyhedra. The V5+, Se4+ (Te4+), and Tl+ cations are in asymmetric coordination environments attributable to second-order Jahn−Teller (SOJT) effects. The V5+ cations undergo intra-octahedral distortions toward an edge (local C2 direction), whereas the Se4+ (Te4+) and Tl+ cations are in distorted coordination environments attributable to their lone-p...

Single crystals of three new layered uranium phosphate fluorides, A(UO2)F(HPO4).xH2O (A = Cs+, Rb+, and K+; x = 0-1) have been synthesized by hydrothermal reactions using UO3, H3PO4, HF, and corresponding alkali metal halides as reagents. Although all three new materials have layered structures, each of them contains different structural motifs within the layer. While Cs(UO2)F(HPO4).0.5H2O and Rb(UO2)F(HPO4) reveal noncentrosymmetric crystal structures, K(UO2)F(HPO4).H2O crystallizes in a centrosymmetric space group. In addition, the ion-exchanged phases for all three materials are highly crystalline. Crystal data: Cs(UO2)F(HPO4).0.5H2O, orthorhombic, space group Pca21 (No. 29), with a = 25.656(5) A, b = 6.0394(12) A, c = 9.2072(18) A, and Z = 4; Rb(UO2)F(HPO4), orthorhombic, space group Cmc21 (No. 36), with a = 17.719(4) A, b = 6.8771(14) A, c = 12.139(2) A, and Z = 8; K(UO2)F(HPO4).H2O, monoclinic, P21/n (No. 14), with a = 6.7885(14) A, b = 8.7024(17) A, c = 12.020(2) A, beta = 94.09(3), and Z = 4.

A new polar ammonium tungsten tellurite, (NH4)2Te2WO8, has been synthesized and structurally characterized. The material was synthesized hydrothermally, using NH4OH, WO3, and TeO2 as reagents, and structurally characterized by single-crystal X-ray diffraction. (NH4)2Te2WO8 crystallizes in the noncentrosymmetric (NCS) polar monoclinic space group P21 (No. 4) with a = 6.9716(9) A, b = 7.0279(9) A, c = 9.4593(13) A, and β = 99.188(2)°. The material exhibits a two-dimensional structure consisting of WO6 octahedra connected to TeO4 polyhedra. Both the W6+ and the Te4+ cations are in asymmetric coordination environments attributable to second-order Jahn−Teller (SOJT) effects. (NH4)2Te2WO8 is NCS; thus second-harmonic generation (SHG) measurements were performed. SHG experiments, using 1064 nm radiation, revealed an efficiency of approximately 250 × α-SiO2. As (NH4)2Te2WO8 is also polar, ferroelectric and pyroelectric measurements were performed. A ferroelectric hysteresis loop (polarization vs electric field) w...