Various Growth Shapes of Na2S2O3 5H2O Crystals

The relation between the growth shapes and supersaturations and/or supercoolings was investigated in the Na₂S₂O₃ 5H₂O crystals: (i) The growth shapes changed from a hexagonal prismatic crystal, aggregate of platy crystals and to a spherulite with an increase of supersaturations and/or supercooloings. (ii) The deposition rate suddenly increased at a certain supersaturation and/or supercooling, where the growth shape changed from the hexagonal prism to the aggregate of platy crystals. (iii) The deposition rates of spherulites become higher with increasing the solute concentrations. (iv) The formation process of the spherulites were in situ observed by the Schlieren and/or Mach‐zehnder interferometer methods.     

CsB3O5(CBO)晶体生长和形貌研究

本文采用籽晶浸没法,在Cs2O过量3;的Cs2O-B2O3体系中生长了CsB3O5单晶.生长参数如下:液面以下温度梯度为0.5℃/cm, 晶体旋转速度为12r/min,降温速率0.2℃/d,可获得透明、无包裹体、无开裂、最大尺寸达65×44×49mm3的CsB3O5单晶.研究了CsB3O5的生长形貌,CsB3O5生长没有明显的方向性,总是呈现长柱状,最易出现的晶面是(011)和(101)晶面.     

NaCo2O4晶体的生长,形貌和生长机理研究（英文）

采用自发成核方法,以NaCl-Na2CO3为助熔剂,生长了毫米级的NaCo2O4晶体。通过X射线衍射对晶体作了表征。利用扫描电子显微镜和原子力显微镜研究了晶体的形貌和生长机理。结果表明:所得晶体是NaCo2O4,属于六方晶系,晶胞参数:a=b=0.2842 nm,c=1.0894 nm,V=0.0761997 nm3。NaCo2O4晶体是沿c轴层状生长的,同时从阴离子配位多面体的角度分析了晶体的形貌。     

Growth of Barium Cerate Crystals from BaCl2 Solution

Barium cerate crystals of 1.5 mm diameter could be grown from melt solutions containing barium chloride, barium oxide (from thermolysis of barium carbonate), and cerium(IV) oxide. The maximum size of the crystals is limited by the low solubility of cerium(IV) oxide in the barium chloride melt (ca. 0.1 Mol%). The flux can be removed by leaching the melt with water. Acid solutions must not be used to avoid decomposition of the barium cerate crystals. Neither congruent melting or incongruent decomposition of the BaCeO₃ crystals could be found up to 1580 degrees centigrade.     

Na5[B2P3O13]晶体双晶结构的研究

采用泡生法和b向籽晶生长出尺寸为22mm×24mm×20mm的透明Na5[B2P3O13]晶体.晶体定向中发现(100)和(001)晶面的一级衍射出现双峰;正交偏光显微镜下观察晶体的(010)切片,看到清晰的明暗条纹;当一束激光正入射(010)切片时,产生衍射现象;用同步辐射白光X射线形貌术拍摄了(100)、(010)和(001)切片的Laue像,观察到了晶体的孪晶结构,再借助(010)切片的化学腐蚀研究,推出该晶体为规则的聚片双晶,其结合面为(001).     

Growth and Characterization of Na2CaGe6O14 Single Crystals

Transparent, crack-free Na₂CaGe₆O₁₄ (NCG) single crystals were successfully grown using the Czcchralski technique. The largest crystal had 30 mm in total length and 18 mm in maximal diameter. Best crystal quality was achieved under low temperature gradient arrangement. The crystal structure of NCG has been refined from single crystal X-ray diffraction data. Some piezoelectric properties of NCG are reported.     

Morphology of β-BaB2O4 (BBO) Crystals in Relation to its Structure and Growth Conditions

β-BaB₂O₄ (BBO) crystals with well-defined morphology have been grown from Na₂O solutions using the top seeded solution growth (TSSG) method. The crystal morphology in relation to its structure and growth conditions has been studied in detail on the basis of crystallography and crystal chemistry. It is found that the morphological characteristics are related to the orientations of structural unit (B₃O₆)^3— anion rings in the crystal. On the other hand, the growth parameters may greatly affect the appearance of faces of the crystal, but the crystals still generally take trigonal in outline and have a diagnostic character of point group 3m. The observed morphology is in disagreement with BFDH and PBC analyses and is explained from the incorporation of the growth units on the faces and facets. Since the incorporation rates of the growth units are different on different faces, the boule habits with well-defined morphology are formed.     

Ho~(3+)∶La_2CaB_(10)O_(19)晶体生长和光谱性能(英文)

采用顶部籽晶法生长Ho3+∶La2CaB10O19晶体。测试了晶体的X射线衍射谱图以及晶体器件的摇摆曲线,半峰宽为21.6 arcsec,晶体结晶质量良好。在室温下测试了吸收光谱、发射光谱和荧光寿命。应用Judd-Ofelt理论评价了Ho3+∶La2CaB10O19晶体的光谱性能。分别计算了Ho3+的唯象强度、谱线强度、辐射寿命、荧光分支比等参数。     

溴化铈晶体的生长与性能研究

采用改进的坩埚下降法生长出φ1.5"×1.5"的无宏观缺陷的溴化铈晶体毛坯.研究测试了溴化铈晶体的荧光光谱、紫外-可见透射光谱及光输出、能量分辨率、本底等闪烁性能.结果表明:在光致激发下,溴化铈晶体的发光主峰位于390 nm;其10 mm厚度样品在390nm处的光透过率为60;;φ1"×1"大小的样品在137Cs源的662 keV伽马射线作用下能量分辨率为4.26;,光输出相当于NaI(Tl)晶体的125;;溴化铈晶体中在0.005 Bq/g探测限下未检测到138La和227Ac元素,本底水平显著低于掺铈溴化镧晶体.     

Growth and Properties of BeO · 3 Al2O3 (BHA) Single Crystals

Large single crystal of BeO · 3 Al₂O₃ (beryllium hexa-aluminate or BHA) doped with chromium up to 20 mm in maximum diameter and 60 mm long were grown by Czochralski method. Thechnological conditions of crystal growth have been introduced and key factor leading to a successful growth is a adequate composition of starting charge mixture other than stoichiometry. The crystal structure, absorption spectra and fluorescence spectra of BHA: Cr³⁺ have been measured. Vibronic side band of the fluorescence spectra is from 700 nm to 900 nm.     

On the Growth Morphology of K2Cr2O7 (KBC) Crystals

The morphology of potassium dichromate (KBC) crystals grown under different conditions by solvent evaporation method is investigated. Observations of the examination of asgrown surfaces and inclusions, and of the realtion between dislocations and inclusions are presented. The results indicate that the change in the morphology of KBC crystals can be associated with the dislocation structure in the crystal.     

La3Ga5SiO14单晶的生长、性能及SAW应用

本文综述了新型压电晶体La3Ga5SiO14的最新研究进展,详细讨论了该晶体的生长问题,简单介绍了该晶体的性能及其在SAW和BAW方面的应用,分析了该晶体在压电应用方面的优势.     

Growth and Character of the Transition Spectrum of Nd-doped K2La(NO3)5 · 2 H2O Crystals

Potassium lanthanum nitrate dihydrate (KLN) is a new nonlinear optical crystal. An Nd-doped potassium lanthanum nitrate (KLNN), was grown. As the first on this crystal and its characters of growth, thermal, spectral, and nonlinear optic properties is reported. KLNN crystal will be a useful material in frequency conversion of generating blue-green laser.     

Crystal Growth,Thermal and Linear Optical Properties of the Non‐Centrosymmetric Hydrated Tetraborates Na2[B4O5(OH)4] . 3H2O (Tincalconite) and K2[B4O5(OH)4] . 2H2O

Large single crystals of the non‐centrosymmetric hydrated tetraborates Na₂[B₄O₅(OH)₄] . 3H₂O (Tincalconite) (point group 32) and K₂[B₄O₅(OH)₄] . 2H₂O(point group 222) were grown from aqueous solutions and the linear optical properties (refractive indices between 365 nm and 1530 nm and unpolarized absorption spectra) as a basis for nonlinear optical investigations were determined. The uniaxial positive sodium salt is not phase matchable; in the orthorhombic potassium compound type I phase matching is possible in the near infrared region. Thermal investigations indicate a phase transition at ≈285 K for Na₂[B₄O₅(OH)₄] . 3H₂O.     

钛宝石晶体的泡生法生长和闪烁发光性能

采用泡生法生长了115 kg级大尺寸钛宝石(Ti:Al2 O3)晶体,晶体外形完整无开裂,制备了口径达?300 mm的高质量大口径钛宝石单晶样品.在X射线和α粒子激发下测试了晶体的闪烁发光性能.结果表明,Ti:Al2 O3晶体的闪烁发光包含近红外和近紫外发光.近红外发光来源于Ti3+特征发射,效率较高,衰减时间慢.近紫...     

Synthesis and Single Crystal X-Ray Structure of [Na(H2O)2(C18H15O6SO3)]2

Abstract  [Na(H₂O)₂(C₁₈H₁₅O₆SO₃)]₂ was synthesized by sulfated 5-hydroxy-6,7,4′-trimethoxyisoflavone with concentrated sulfuric acid. Single-crystal X-ray diffraction study indicates that it is a dimeric centrosymmetric species. The coordination polyhedron of each Na(I) atom exhibits a distorted trigonal bipyramidal geometry. The dimeric units are linked by intermolecular hydrogen bonds C–H⋯π, C–H⋯O and O–H⋯O to result in a three-dimensional framework. Graphical Abstract  [Na(H₂O)₂(C₁₈H₁₅O₆SO₃)]₂ was synthesized by sulfated 5-hydroxy-6,7,4′-trimethoxyisoflavone with concentrated sulfuric acid. The coordination polyhedron of each Na(I) atom exhibits a distorted trigonal bipyramidal geometry. The dimeric centrosymmetric units are linked by intermolecular hydrogen bonds C–H⋯π, C–H⋯O and O–H⋯O to result in a three-dimensional framework. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Na3Sm2(BO3)3的晶体生长及热学和光谱性质

以Na2CO3-H3BO3为助溶剂,用顶部籽晶法生长了14mm×8mm×2mm的Na3Sm2(BO3)3晶体.差热分析(DTA)表明Na3Sm2(BO3)3非同成分熔融,熔点为1089.1℃.该晶体易溶于酸,在空气条件下能稳定存在,不易潮解.测量了室温下晶体在200～2500nm范围内的吸收光谱,并对跃迁能级进行了初步指认.     

非线性光学晶体Na3La9O3(BO3)8的生长研究

以Na3CO3和H3BO3为助熔剂,Na3CO3和H3BO3摩尔比为7/6,熔质Na3La9O3(BO3)8和助熔剂摩尔比为1/10～1/14,采用顶部籽晶生长方法,生长Na3La9O3(BO3)8晶体,晶体尺寸为30×18×8mm3.本文讨论了籽晶方向对Na3La9O3(BO3)8晶体生长的影响,(100)方向比(001)方向更有利于晶体生长.     

Vertical Bridgman Growth and Scintillation Properties of Doped Bi4Si3O12 Crystals

Pure BSO and Ce, Nd, Eu, Cr and Fe doped BSO crystals of high optical quality with 20x20x100mm³ have been grown by the vertical Bridgman method. After measuring their transmission spectra, light outputs, FWHM energy resolutions and excitation-emission spectra, we summarized and explained the laws of doped effects on the scintillation characteristics. we can expect that Eu may be the most promising dopant candidate of the doped elements for improving the scintillation characteristics of BSO crystal.