The crystal structure of di-hydroxyisobutyrate)diaquo neodymium nitrate Nd(C_4H_7O_3)_2NO_32H_2O was determined by X-ray diffraction analysis. It belongs to monoclinic,space group C2/C,with cell dimensionsa=8.996(1), ...The crystal structure of di-hydroxyisobutyrate)diaquo neodymium nitrate Nd(C_4H_7O_3)_2NO_32H_2O was determined by X-ray diffraction analysis. It belongs to monoclinic,space group C2/C,with cell dimensionsa=8.996(1), b=8.601(1),c=21.111(3),β=92.38°,V=1632.O,Z=4,D_c=1.83g/cm^3.Crystal structure has been refined by full-matrix least-square techniques giving a final R value of 0.036.The neodymium atom is coordinated to eight oxygen atoms.The nitrate group in complex is not bonded to neodymium,each two neodymium atoms are linked by bridging carboxyl group forming a chain polymeric molecule.展开更多
The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.5...The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.599×10-20 cm2 and ?6 = 5.139×10-20 cm2. The fluorescence branch rations were also obtained: β1 = 0.424, β2 = 0.474, β3 = 0.094 and β4 = 0.005. The radiative lifetime is 416 μs and quantum efficiency ηc 9.13%. The emission cross section σp (1.06 μm) is 4.38×10-19 cm2.展开更多
Three novel 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles were designed,synthesized and characterized by IR,NMR and APCI-MS.3-o-Fluorophenyl-6-（4-decarboxydehydroabietyl）-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole（6a,C28H3...Three novel 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles were designed,synthesized and characterized by IR,NMR and APCI-MS.3-o-Fluorophenyl-6-（4-decarboxydehydroabietyl）-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole（6a,C28H31FN4S） was structurally determined by single-crystal X-ray diffraction.The crystal belongs to the orthorhombic system,space group P212121 with a=6.0153（14）,b=12.2577（19）,c=34.055（3）A,V=2511.0（7）A^3,Z=4,Mr=474.63,Dc=1.255Mg/m^3,λ=0.71073 A,μ（MoKα）=0.160 mm^-1,F（000）=1008,the final R=0.0555 and wR=0.1248 for 3094 observed reflections with I〉2σ（I）.There are six rings in the crystal structure of the title compound.The dihedral angle between 1,2,4-triazole and 1,3,4-thiadiaole rings is 1.4o,and that between 1,2,4-triazole and benzene ring D 25.5o.展开更多
Growth and morphology of neodymium or ytterbium doped calcium gadolinium yttrium oxoborate (Re∶Ca 4Gd x Y 1- x O(BO 3) 3(Re∶GdYCOB)Re =Nd,Yb; x =0-1)were systematically studied. Polycrystalline materials used for Re...Growth and morphology of neodymium or ytterbium doped calcium gadolinium yttrium oxoborate (Re∶Ca 4Gd x Y 1- x O(BO 3) 3(Re∶GdYCOB)Re =Nd,Yb; x =0-1)were systematically studied. Polycrystalline materials used for Re∶GdYCOB single crystals growth were synthesized by multistage solid phase reaction method.Re∶GdYCOB single crystals were grown by Czochralski technique.The pulling rates are 0.5-2mm/h and the rotation rates are 10-30r/min.Usually 65-75% polycrystalline materials can be transformed into good quality single crystals under our growth conditions. The structures of some as grown Re∶GdYCOB single crystals were measured by using a four circle diffractometer.The results measured show that the space group of the crystals is C 3 s Cm.The determined lattice constants of 8 at% Nd doped Ca 4YO(BO 3) 3 single crystal are a =0.8076nm, b =1.6020nm, c =0.3527nm , β =101.23°.展开更多
The crystal Nd 3+∶Sr 6YSc(BO 3) 6 was grown by the top-seeded solution growth method from a Li 6B 4O 9 flux. The s pectral properties of Nd 3+∶Sr 6YSc(BO 3) 6 crystal were investigated. Using Judd-Ofel...The crystal Nd 3+∶Sr 6YSc(BO 3) 6 was grown by the top-seeded solution growth method from a Li 6B 4O 9 flux. The s pectral properties of Nd 3+∶Sr 6YSc(BO 3) 6 crystal were investigated. Using Judd-Ofelt theory to ana lyze the optical strength measured in absorption spectrum, the following spectr al parameters were obtained: parameters of oscillator strengths Ω λ are Ω 2=1.194×10 -20 cm2, Ω 4=4.186×10 -20 cm2 and Ω 6=3.3 51×10 -20 cm2. The radiative lifetime is 322 μs, and the fluorescence b ranch ratios were calculated: β 1=0.465, β 2=0.453, β 3=0.079 and β 4=0.004. The results indicate that Nd 3+∶Sr 6YSc(BO 3) 6 c rystal seems to be a potential high-efficient laser material.展开更多
Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ ...Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ emission by Nd3＋ absorption lines was ob- served. The assignments of f-f and d-d transitions were proposed. The broad emission band of chromium ions is an indication that weak/intermediate crystal field strength is present at the Cr3＋ site.展开更多
BiB3O6 (BIBO) single crystals with sizes of 44 mm × 24 mm × 10 mm and weight of 24.7 g have been successfully grown by the top-seeded method. In this note, the preparation of seed, the growth of crystal and ...BiB3O6 (BIBO) single crystals with sizes of 44 mm × 24 mm × 10 mm and weight of 24.7 g have been successfully grown by the top-seeded method. In this note, the preparation of seed, the growth of crystal and some problems encountered are reported. The lattice parameters of BIBO are a =7.1203(7)A, b = 4.9948(7)A, c = 6.5077(7)A, β= 105.586(8) ", V=222.93(5)A3, which were determined by BRUKER-P4 four-circle diffractometer. BIBO is biaxial crystal and the relative orientation of (X, Y, Z) with regard to (a, b, c) is: X|| b, (Y, c) =47.2°, (Z, a) = 31.6°, determined by the X-ray analysis combined with polarized microscopy. The second-harmonic-generation (SHG) conversion efficiency of the sample for 1.064 μm light is up to 67.7%. We have also obtained the third harmonic generation (THG) of 1.064 μm, namely, 1.064 μm + 0.532 μn →0.355 μm. BIBO crystal is free of moisture and hygroscopy.展开更多
Transparent Nd : BiB3O6 crystal has been grown by top-seeded method. The refraction indices of the crystal were measured and the parameters of chromatic dispersion were fitted. The room temperature absorption spectra ...Transparent Nd : BiB3O6 crystal has been grown by top-seeded method. The refraction indices of the crystal were measured and the parameters of chromatic dispersion were fitted. The room temperature absorption spectra of the crystal have been measured and compared with that of 0.2 mol/L NdCI3 solution. According to Judd-Ofelt (JO) theory, the spectral strength parameters Ω2 = 0.1776×10-20 cm2, Ω4 = 0.1282×10-20 cm2 and Ω6 = 0.1357×10-20 cm2 of Nd3+ ion were fitted. The radiative transition probabilities AJ,(?), oscillator strengths fJ,(?), radiative lifetime T and the branching ratio β(?) have all been calculated. Based on these parameters, the properties and application perspective are discussed.展开更多
The crystal structure of a new type arylarsonic polytungstate[C(NH_)_]_4[p-NH_3C_6H_4As)_2- W_6O_(25)]·4H_O was determined by single-crystal X-ray diffraction analysis.It belongs to triclinic,space group P,with c...The crystal structure of a new type arylarsonic polytungstate[C(NH_)_]_4[p-NH_3C_6H_4As)_2- W_6O_(25)]·4H_O was determined by single-crystal X-ray diffraction analysis.It belongs to triclinic,space group P,with cell dimensions a=12.863(3),b=18.912(3),c=21.383(4)α=91.14(2)°,β= 93.65(3)°,γ=92.25(3)°,V=5185.9~3,Z=4,D_c=2.753g/cm^3.The intensity data were collected on an Enraf-Nonius CAD4 diffractometer with Mo Kα radiation.The positions of all tungsten and arsenic atoms were determined by direct method.The other non-hydrogen atoms were revealed by difference Fourier synthesis.The structure was refined by fullmatrix least-squares procedure to a final R value of 0.070.The crystal structure contains two similar but nonidentical molecules.Two similar anions consist of a ring of six WO_6 octahedra,which are connected with one face-sharing,two corner-sharings and three edge-sharings,and two p-aminophenylarsonic tetrahedra capped above and below the ring. In each WO_6 ring,four tungsten atoms,which are joined with edge-sharing oxygen atoms,are almost coplanar,while the two others,which are joined with face-sharing oxygen atoms,protrude out of the ring towards the same side.The two arsenic atoms in each anion are not equivalent in their bonding manner.In each anion,all non-hydrogen atoms of each organic group are in the same plane.Each molecule contains one anion,four C(NH_2)_3^+ cations and four water molecules.There are many hydrogen bonds between cations and anions throughout the whole crystal.The amino groups can accept protons,so that the charge of the resulting anion decreases and[(RAs)_2W_6O_(25)]^(4-)type complexes are formed.展开更多
文摘The crystal structure of di-hydroxyisobutyrate)diaquo neodymium nitrate Nd(C_4H_7O_3)_2NO_32H_2O was determined by X-ray diffraction analysis. It belongs to monoclinic,space group C2/C,with cell dimensionsa=8.996(1), b=8.601(1),c=21.111(3),β=92.38°,V=1632.O,Z=4,D_c=1.83g/cm^3.Crystal structure has been refined by full-matrix least-square techniques giving a final R value of 0.036.The neodymium atom is coordinated to eight oxygen atoms.The nitrate group in complex is not bonded to neodymium,each two neodymium atoms are linked by bridging carboxyl group forming a chain polymeric molecule.
基金This work was supported by the National Natural Science Foundation of China (50272066) and Key Project of Science and Technology of Fujian Province (2001H107)
文摘The absorption and emission spectra of Nd3+:GdMgB5O10 crystal were inves- tigated. Based on Judd-Ofelt theory the three parameters of oscillator strength were obtained as follows: ?2 = 2.099×10-20 cm2, ?4 = 4.599×10-20 cm2 and ?6 = 5.139×10-20 cm2. The fluorescence branch rations were also obtained: β1 = 0.424, β2 = 0.474, β3 = 0.094 and β4 = 0.005. The radiative lifetime is 416 μs and quantum efficiency ηc 9.13%. The emission cross section σp (1.06 μm) is 4.38×10-19 cm2.
基金Supported by the Foundation of 100 Young and Middle-aged Discipline Leaders of Guangxi Province in the 21st century (No 2004219)the Natural Science Foundation of Guangxi Province (No 0731054)
文摘Three novel 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles were designed,synthesized and characterized by IR,NMR and APCI-MS.3-o-Fluorophenyl-6-（4-decarboxydehydroabietyl）-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole（6a,C28H31FN4S） was structurally determined by single-crystal X-ray diffraction.The crystal belongs to the orthorhombic system,space group P212121 with a=6.0153（14）,b=12.2577（19）,c=34.055（3）A,V=2511.0（7）A^3,Z=4,Mr=474.63,Dc=1.255Mg/m^3,λ=0.71073 A,μ（MoKα）=0.160 mm^-1,F（000）=1008,the final R=0.0555 and wR=0.1248 for 3094 observed reflections with I〉2σ（I）.There are six rings in the crystal structure of the title compound.The dihedral angle between 1,2,4-triazole and 1,3,4-thiadiaole rings is 1.4o,and that between 1,2,4-triazole and benzene ring D 25.5o.
文摘Growth and morphology of neodymium or ytterbium doped calcium gadolinium yttrium oxoborate (Re∶Ca 4Gd x Y 1- x O(BO 3) 3(Re∶GdYCOB)Re =Nd,Yb; x =0-1)were systematically studied. Polycrystalline materials used for Re∶GdYCOB single crystals growth were synthesized by multistage solid phase reaction method.Re∶GdYCOB single crystals were grown by Czochralski technique.The pulling rates are 0.5-2mm/h and the rotation rates are 10-30r/min.Usually 65-75% polycrystalline materials can be transformed into good quality single crystals under our growth conditions. The structures of some as grown Re∶GdYCOB single crystals were measured by using a four circle diffractometer.The results measured show that the space group of the crystals is C 3 s Cm.The determined lattice constants of 8 at% Nd doped Ca 4YO(BO 3) 3 single crystal are a =0.8076nm, b =1.6020nm, c =0.3527nm , β =101.23°.
文摘The crystal Nd 3+∶Sr 6YSc(BO 3) 6 was grown by the top-seeded solution growth method from a Li 6B 4O 9 flux. The s pectral properties of Nd 3+∶Sr 6YSc(BO 3) 6 crystal were investigated. Using Judd-Ofelt theory to ana lyze the optical strength measured in absorption spectrum, the following spectr al parameters were obtained: parameters of oscillator strengths Ω λ are Ω 2=1.194×10 -20 cm2, Ω 4=4.186×10 -20 cm2 and Ω 6=3.3 51×10 -20 cm2. The radiative lifetime is 322 μs, and the fluorescence b ranch ratios were calculated: β 1=0.465, β 2=0.453, β 3=0.079 and β 4=0.004. The results indicate that Nd 3+∶Sr 6YSc(BO 3) 6 c rystal seems to be a potential high-efficient laser material.
基金supported by Ministry of Science and Higher Education (N N507 372335)
文摘Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ emission by Nd3＋ absorption lines was ob- served. The assignments of f-f and d-d transitions were proposed. The broad emission band of chromium ions is an indication that weak/intermediate crystal field strength is present at the Cr3＋ site.
基金This work was supported by the State Key Program of China.
文摘BiB3O6 (BIBO) single crystals with sizes of 44 mm × 24 mm × 10 mm and weight of 24.7 g have been successfully grown by the top-seeded method. In this note, the preparation of seed, the growth of crystal and some problems encountered are reported. The lattice parameters of BIBO are a =7.1203(7)A, b = 4.9948(7)A, c = 6.5077(7)A, β= 105.586(8) ", V=222.93(5)A3, which were determined by BRUKER-P4 four-circle diffractometer. BIBO is biaxial crystal and the relative orientation of (X, Y, Z) with regard to (a, b, c) is: X|| b, (Y, c) =47.2°, (Z, a) = 31.6°, determined by the X-ray analysis combined with polarized microscopy. The second-harmonic-generation (SHG) conversion efficiency of the sample for 1.064 μm light is up to 67.7%. We have also obtained the third harmonic generation (THG) of 1.064 μm, namely, 1.064 μm + 0.532 μn →0.355 μm. BIBO crystal is free of moisture and hygroscopy.
基金the National Natural Science Foundation of China (Grant No. 59823003).
文摘Transparent Nd : BiB3O6 crystal has been grown by top-seeded method. The refraction indices of the crystal were measured and the parameters of chromatic dispersion were fitted. The room temperature absorption spectra of the crystal have been measured and compared with that of 0.2 mol/L NdCI3 solution. According to Judd-Ofelt (JO) theory, the spectral strength parameters Ω2 = 0.1776×10-20 cm2, Ω4 = 0.1282×10-20 cm2 and Ω6 = 0.1357×10-20 cm2 of Nd3+ ion were fitted. The radiative transition probabilities AJ,(?), oscillator strengths fJ,(?), radiative lifetime T and the branching ratio β(?) have all been calculated. Based on these parameters, the properties and application perspective are discussed.
文摘The crystal structure of a new type arylarsonic polytungstate[C(NH_)_]_4[p-NH_3C_6H_4As)_2- W_6O_(25)]·4H_O was determined by single-crystal X-ray diffraction analysis.It belongs to triclinic,space group P,with cell dimensions a=12.863(3),b=18.912(3),c=21.383(4)α=91.14(2)°,β= 93.65(3)°,γ=92.25(3)°,V=5185.9~3,Z=4,D_c=2.753g/cm^3.The intensity data were collected on an Enraf-Nonius CAD4 diffractometer with Mo Kα radiation.The positions of all tungsten and arsenic atoms were determined by direct method.The other non-hydrogen atoms were revealed by difference Fourier synthesis.The structure was refined by fullmatrix least-squares procedure to a final R value of 0.070.The crystal structure contains two similar but nonidentical molecules.Two similar anions consist of a ring of six WO_6 octahedra,which are connected with one face-sharing,two corner-sharings and three edge-sharings,and two p-aminophenylarsonic tetrahedra capped above and below the ring. In each WO_6 ring,four tungsten atoms,which are joined with edge-sharing oxygen atoms,are almost coplanar,while the two others,which are joined with face-sharing oxygen atoms,protrude out of the ring towards the same side.The two arsenic atoms in each anion are not equivalent in their bonding manner.In each anion,all non-hydrogen atoms of each organic group are in the same plane.Each molecule contains one anion,four C(NH_2)_3^+ cations and four water molecules.There are many hydrogen bonds between cations and anions throughout the whole crystal.The amino groups can accept protons,so that the charge of the resulting anion decreases and[(RAs)_2W_6O_(25)]^(4-)type complexes are formed.
