Showing papers by "Hong Liu published in 2001"
TL;DR: In this article, a monoclinic crystal of BiB 3 O 6 with dimensions of 44×24×10mm 3 has been grown by the top-seeded method and the wavelength range of transparency is presented for the first time.
56 citations
TL;DR: In this article, a self-frequency-doubling Yb-doped yttrium aluminium tetraborate (Yb:YAB) was grown by flux method, with large sizes and good optical quality as well as different Yb 3+ ion densities in the lattice structure.
51 citations
TL;DR: In this article, the transmittance spectra along different phase matching (PM) directions were measured in the range of 190-3200nm and their second-harmonic generation (SHG) properties were measured.
47 citations
TL;DR: In this paper, the Raman spectra for partially filled skutterudite La x Fe 3 CoSb 12 (x = 0.2, 0.4, 0.6, and 0.8) at room temperature have been obtained.
32 citations
TL;DR: In this paper, the morphological faces are characterized by X-ray diffraction methods and the problem of layer growth habit is solved by the selection of a suitable flux. And additional flux-systems are also discussed.
14 citations
TL;DR: Skutterudite Na1+xFe4P12 whiskers were prepared by a new hydrothermal reduction alloying method as mentioned in this paper, the diameter of the whisker is about 0.5−4 μm and its L/D ratio is about 10−20.
Abstract: Skutterudite Na1+xFe4P12 whiskers were prepared by a new hydrothermal reduction alloying method. The diameter of the whisker is about 0.5−4 μm and its L/D ratio is about 10−20. Heating temperature ...
9 citations
TL;DR: Based on atomic force microscopy (AFM) observations, a check-like twin structure in self-frequency-doubling laser crystal material Yb:YAl3(BO3)4 (YbYAB) was found as discussed by the authors.
Abstract: Twin structure is a defect in the self-frequency-doubling laser crystal material Yb:YAl3(BO3)4 (YbYAB). Based on atomic force microscopy (AFM) observations, a check-like twin structure in YbYAB crystals is found. This kind of twin structure has three twin composition planes: (10\bar{1}1), (0\bar{1}11) and (\bar{1}101). These three twin composition planes result in a series of twin boundaries in two directions, forming a check-like pattern on each face. From the orientation of the chemical etching pits on each side of the twin boundary, it is found that the twin element is `twin plane ⊥ y axis', alternatively indicated as `twin plane {11\bar{2}0}'. The two single crystals composing the twin are a right form and a left form. This kind of twin is similar to the Brazil twin found in quartz.
8 citations
TL;DR: In this paper, the growth defects of YbxY1-xAl3(BO3)(4) (x = 0.1, 0.07 and 0) crystals have been detected by X-ray topography.
6 citations
TL;DR: In this article, a sub-grain boundary in the GdCa4O(BO3)(3) crystal has been found and the formation mechanism of subgrain boundary is discussed.
5 citations
08 Jun 2001
TL;DR: In this article, the effect of the filling fraction on the transport properties of skutterudite material was investigated, and it was found that the partially filled skutteruda with lower filling fraction has better electric transport properties than fully filled skatteruda with higher filling fraction.
Abstract: The progress in skutterudite-based thermoelectric materials in our group is reviewed. The effect of the filling fraction on the transport properties of skutterudite material was investigated. It has been found that the partially filled skutterudite with lower filling fraction has better electric transport properties than fully filled skutterudite. Raman scattering investigations on filled skutterudite with different filling fractions has indicated that the rattling degree of the filling atoms in the voids in skutterudite decreases with the increase of the filling fraction. Filled skutterudite NaFe/sub 4/P/sub 12/ nanowires of 25-80 nm in diameter and 500-4000 nm in length have been obtained by using novel hydrothermal-reduction-alloying method. The nanowire can be arrayed directionally the magnetic field. A polyaniline/skutterudite thermoelectric composite was synthesized by using an in situ compounding method. An investigation into the electric transport properties of the composite has been carried out.
5 citations
TL;DR: In this article, the top-seeded 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 topseeded method.
Abstract: 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 area =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 µm →0.355 µm. BIBO crystal is free of moisture and hygroscopy.
TL;DR: In this article, a BiB3O6 crystal has been grown by top-seeded method and the refraction indices of the crystal were measured and the parameters of chromatic dispersion were fitted.
Abstract: 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 NdCl3 solution. According to Judd-Ofelt (JO) theory, the spectral strength parameters Ω2 = 0.1776×10−20 cm2, Ω4 = 0.1282−10−201 cm2 and Ω6 = 0.1357X10-20 cm2 of Nd3+ ion were fitted. The radiative transition probabilities AJ,J’, oscillator strengths fJ,J’, radiative lifetime rand the branching ratio βJ’ have all been calculated. Based on these parameters, the properties and application perspective are discussed.
08 Jun 2001
TL;DR: In this article, a growth mechanism of NaFe/sub 4/P/sub 12/ nanowires was proposed and high-resolution transmission electron microscope (HRTEM) was used to investigate the microstructure of the nanowire.
Abstract: Filled skutterudite NaFe/sub 4/P/sub 12/ single crystal nanowires were synthesized by using a hydrothermal-reduction-alloying method. X-ray diffraction (XRD), Electron diffraction (ED), Raman scattering, as well as elemental analysis were used to characterize the product. High-resolution transmission electron microscope (HRTEM) was used to investigate the microstructure of the nanowire. A growth mechanism of NaFe/sub 4/P/sub 12/ nanowire was proposed.
08 Jun 2001
TL;DR: In this paper, the authors used X-ray diffraction, infrared spectra, thermal gravity analysis (TGA) transmission electron microscope (TEM) and electron diffraction (ED) to characterize polyaniline and the composites.
Abstract: Polyaniline/NaFe/sub 4/P/sub 12/ whiskers and polyaniline/NaFe/sub 4/P/sub 12/ nanowire composites were prepared by an in situ compounding method. X-ray diffraction (XRD), infrared spectra, thermal gravity analysis (TGA) transmission electron microscope (TEM) and electron diffraction (ED) were used to characterize polyaniline and the composites. Polyaniline can grow on the surface of NaFe/sub 4/P/sub 12/ whisker and forms a novel "brush" structure. The mechanism of the forming of the "brush" structure is suggested. The conductivity and Seebeck coefficient of polyaniline and the composites were measured.