The title compound belongs to monoclinic, space group C2/c with a = 5.2694（1）, b = 12.6659（4）, c = 19.4108（2） A,β= 91.504（2）°, V = 1295.06（5） A^3, Z = 4 and Dc= 5.599 g/cm^3. The structure of BaGd2（M...The title compound belongs to monoclinic, space group C2/c with a = 5.2694（1）, b = 12.6659（4）, c = 19.4108（2） A,β= 91.504（2）°, V = 1295.06（5） A^3, Z = 4 and Dc= 5.599 g/cm^3. The structure of BaGd2（MoO4）4 contains a MoO4 tetrahedron, a distorted GdO8 polyhedron, and Ba^2＋ ions in a tenfold coordination. The GdO8 polyhedra are linked together through edge-sharing to give a two-dimensional Gd layer. The MoO4 tetrahedra connected to the Gd atoms are capped up and down the Gd layer through common oxygen apices, thus-forming a new Gd-Mo layer. Finally, the Gd-Mo layers are held together through bridging BaO10 polyhedra to form a three-dimensional framework. Since the Ba-μ3-O bond has a large average distance of 2.888 A, this structural characteristic will result in a cleavage along the （001） plane.展开更多
Single crystal of Li2Zn2（MoO4）3 has been grown from a flux of Li2MoO4 by the top-seeded solution-growth method, and its stnicture was refined by the Rietveld method. It belongs to the orthorhombic system, space grou...Single crystal of Li2Zn2（MoO4）3 has been grown from a flux of Li2MoO4 by the top-seeded solution-growth method, and its stnicture was refined by the Rietveld method. It belongs to the orthorhombic system, space group Pnma with a = 5.1114, b = 10.4906 and c = 17.6172A. Good agreement between the experimental and calculated profile （Rp = 6.69%, Rwp = 9.73% and Rexp = 6.58%） was reached.展开更多
By using Tb407 and MoO3 as starting materials, ferroelectric Tb2（MoO4）3 crystal was grown by the Czochralski method. The as-grown crystal was pale green color, transparent and crack-free. X-ray powder diffraction （...By using Tb407 and MoO3 as starting materials, ferroelectric Tb2（MoO4）3 crystal was grown by the Czochralski method. The as-grown crystal was pale green color, transparent and crack-free. X-ray powder diffraction （XRPD）, transmission spectrum, dielectric constant and polarization-electric field （P-E） hysteresis loop measurements were performed to characterize the crystal. The XRPD confirmed the as-grown crystal to be Tb2（MoO4）3. The transmission spectrum of the crystal showed that its transmittance in the entire visible and most near-infrared region was more than 70% except for an absorption peak around 486 nm. Obvious dielectric anomaly could be observed at low frequencies with increasing temperature through the dielectric constant measurement and the Curie temperature of Tb2（MoO4）3 crystal was determined to be 162.3℃ The unsaturated P-E hysteresis loops indicated that it was difficult for the ferroelectric domains in Tb2（MoO4）3 crystal to array regularly with repeated switching of the electric field.展开更多
A Sr3Yb2（BO3）4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 （BO3）4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space gro...A Sr3Yb2（BO3）4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 （BO3）4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pnma with a=7.3750（8）, b=15.9265（14）, c=8.6776（9）, V=1019.25（18）3 , Mr=844.18, Z=4, Dc=5.501 g/cm3 , λ（MoKa）=0.71073, μ= 33.835 mm-1 , F（000）=1480, the final R=0.0339 and wR=0.0907 for 1090 observed reflections with I〉2σ（I）. The structure features a three-dimensional framework composed of isolated BO3 planar triangles bridged by YbO8 and SrO8 polyhedra. The Sr2＋ and Yb3＋ occupy statistically three independent sites with a Cm and two C1 local symmetries.展开更多
基金the National Natural Science Foundation of China (No. 60378031)Key Project of Science and Technology of Fujian Province (2001F004)
文摘The title compound belongs to monoclinic, space group C2/c with a = 5.2694（1）, b = 12.6659（4）, c = 19.4108（2） A,β= 91.504（2）°, V = 1295.06（5） A^3, Z = 4 and Dc= 5.599 g/cm^3. The structure of BaGd2（MoO4）4 contains a MoO4 tetrahedron, a distorted GdO8 polyhedron, and Ba^2＋ ions in a tenfold coordination. The GdO8 polyhedra are linked together through edge-sharing to give a two-dimensional Gd layer. The MoO4 tetrahedra connected to the Gd atoms are capped up and down the Gd layer through common oxygen apices, thus-forming a new Gd-Mo layer. Finally, the Gd-Mo layers are held together through bridging BaO10 polyhedra to form a three-dimensional framework. Since the Ba-μ3-O bond has a large average distance of 2.888 A, this structural characteristic will result in a cleavage along the （001） plane.
基金the National Natural Science Foundation of China (No. 50672123)
文摘Single crystal of Li2Zn2（MoO4）3 has been grown from a flux of Li2MoO4 by the top-seeded solution-growth method, and its stnicture was refined by the Rietveld method. It belongs to the orthorhombic system, space group Pnma with a = 5.1114, b = 10.4906 and c = 17.6172A. Good agreement between the experimental and calculated profile （Rp = 6.69%, Rwp = 9.73% and Rexp = 6.58%） was reached.
基金supported by the National Natural Science Foundation of China (50590401)
文摘By using Tb407 and MoO3 as starting materials, ferroelectric Tb2（MoO4）3 crystal was grown by the Czochralski method. The as-grown crystal was pale green color, transparent and crack-free. X-ray powder diffraction （XRPD）, transmission spectrum, dielectric constant and polarization-electric field （P-E） hysteresis loop measurements were performed to characterize the crystal. The XRPD confirmed the as-grown crystal to be Tb2（MoO4）3. The transmission spectrum of the crystal showed that its transmittance in the entire visible and most near-infrared region was more than 70% except for an absorption peak around 486 nm. Obvious dielectric anomaly could be observed at low frequencies with increasing temperature through the dielectric constant measurement and the Curie temperature of Tb2（MoO4）3 crystal was determined to be 162.3℃ The unsaturated P-E hysteresis loops indicated that it was difficult for the ferroelectric domains in Tb2（MoO4）3 crystal to array regularly with repeated switching of the electric field.
基金Supported by the National Natural Science Foundation of China (51002152)the Natural Science Foundation of Fujian Province (2010J05125)
文摘A Sr3Yb2（BO3）4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 （BO3）4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pnma with a=7.3750（8）, b=15.9265（14）, c=8.6776（9）, V=1019.25（18）3 , Mr=844.18, Z=4, Dc=5.501 g/cm3 , λ（MoKa）=0.71073, μ= 33.835 mm-1 , F（000）=1480, the final R=0.0339 and wR=0.0907 for 1090 observed reflections with I〉2σ（I）. The structure features a three-dimensional framework composed of isolated BO3 planar triangles bridged by YbO8 and SrO8 polyhedra. The Sr2＋ and Yb3＋ occupy statistically three independent sites with a Cm and two C1 local symmetries.
