钛酸钾纳米线先驱水热合成六脚状钛酸钡纳米晶（英文）

首次以钛酸钾纳米线为先驱体水热合成了六脚状钛酸钡纳米晶,高分辨透射电镜分析表明六脚状钛酸钡纳米晶为单晶结构,沿[100]方向生长,探讨了钛酸钾纳米线先驱体对于六脚状钛酸钡纳米晶形成的重要作用。     

偏钛酸为原料烧结法制备超细六钛酸钾晶须

采用偏钛酸(H2TiO3)和碳酸钾(K2CO3)为原料,研究不同碳酸钾和偏钛酸中TiO2的摩尔比(n(K2CO3)/n(TiO2))、不同焙烧温度和焙烧时间对产物钛酸钾晶型与形貌的影响,并利用XRD和SEM对其相组成及形貌进行分析。结果表明,以偏钛酸为原料六钛酸钾的最佳合成工艺条件为:n(K2CO3)/n(TiO2)为1/3.5,经过(900℃,1h) (1000℃,2h) (1100℃,2h) (1150℃,2h)高温下焙烧,即可得到平均直径为0.62μm、平均长度为11.06μm的六钛酸钾晶须。产物中六钛酸钾晶须的含量高达97.1%。合成的六钛酸钾晶须亮度为87.26,具有良好的白色颜料性能。     

六钛酸钾晶须制备新工艺

用喷雾干燥-烧结法一次煅烧直接合成了长径比大于10,形貌优良的六钛酸钾晶须,研究了钛钾比、煅烧温度以及保温时间对晶须生长的影响.得出制备六钛酸钾晶须的最佳条件:TiO2与K2CO3的摩尔比为5.5,煅烧温度为1150℃,保温时间为10 h.     

K2Ti6O13纳米线的合成及微观结构分析

通过TiO2与氢氧化钾溶液反应成功制备出Ф9nm、长度约0．6～2μm的结晶度良好的K2Ti6O13纳米线材料。应用X射线衍射仪、高分辨电子显微镜和电子能量损失谱分析了纳米线的微观结构。结果表明纳米线的结构属于K2Ti6O13,类型,晶体结构属单斜晶系,空间群为C2／M,具有层状结构,K2Ti6O13,纳米线的生长方向平行于[010]晶向。     

(SiCW+B4Cp)/MB15 Mg基复合材料的微观结构

利用高分辨电镜研究了(SiCw+B4Cp)/MB15 Mg合金基复合材料的微观结构.SiC晶须的表面附着呈截角八面体形状的MgO纳米颗粒.此外,MgB2和MgO共生在SiC晶须的表面,三者之间存在固定的晶体学取向关系[110]SiC∥[110]MgO∥[1120]MgB2和(111SiC∥(111MgO∥(0001MgB2.MgB2相呈六角盘状几何外形,在Mg合金中其界面能的各向异性显著.此外,还发现了SiC和Mg存在的一种晶体学取向关系[111]siC∥[0001]Mg和(202)siC∥(1120)Mg.研究结果表明,在Mg合金复合材料中,SiC比B4C更加稳定.     

两相界面几何错配的高分辨电子显微象分析

从界面两相的几何参数出发,计算界面两侧点阵平面的错配,并用实验观测的界面位错排布加以证实,这是相间界面分析的常用方法。本文进一步分析了那些从几何失配来预言界面会出现失配位错,但高分辨电子显微象却显示良好匹配的情况。说明在一定条件下,两相的结构相似性会容纳较大的几何失配。     

复合片的XPS和X射线衍射分析

用XPS技术和X射线衍射方法检测了复合片中各个元素的结合能与晶体结构的变化，讨论了复合片与质量有关的问题。     

Phase Transformations in Low-Fe Alloys of the Al-Cu-Fe System

Microstructure and phase transformation in the Al-Cu-Fe alloys of the approximate compositional range of 20-50 at.% Cu and 2 - 10 Fe at.% have been investigated from samples quenched from their respective temperatures by means of different thermal analysis, magnetothermal analysis, scanning electron microscopy, electron probe analysis and powder X-ray diffraction. Representative phase transformations categorized as polymorphic, discontinuous precipitation,quasi-binary eutectoid, and ternary transitional U-type phase transformation are presented. These phase transformations were found to have a common feature which consumes the β phase and appears the φ phase. A schematic diagram was proposed to demonstrate the transition processes with decreasing temperature.     

焙烧温度对K2Ti6O13薄膜光电化学和光催化的影响

采用溶胶凝胶法在导电玻璃上制备K2Ti6O13薄膜,考察焙烧温度对薄膜结构和光催化、光电化学行为的影响。采用XRD和AFM测定晶体和表面结构;以自组装在薄膜表面的十八烷基三氯硅烷（OTS）为光催化降解对象,评价K2Ti6O13薄膜光催化氧化性能;通过计时电位,循环伏安和光电流表征薄膜中光生载流子行为。结果表明,合适的结晶度和晶粒尺寸的匹配使500℃焙烧的K2Ti6O13薄膜具有较高的载流子激发、分离和迁移能力,体现出最高的光催化氧化能力和最大的光电流,光催化性能优于TiO2薄膜。由光电测试计算得其在254 nm光照下光电量子效率约为6.9%。     

Ca2KNa（PO4）2结构的大角度XRD测定

通过大角度的粉末X射线衍射测定了正磷酸钠钾钙[(Ca2KNa(PO4)2)]晶体陶瓷的晶格参数，分析化学纯度的碳酸钙，磷酸二氢钾、磷酸二氢钠按照2：1：1的摩尔比混合后于1300摄氏度高温反应4h，得到了组合符合Ca2KNa(PO4)2的正磷酸钠钾钙陶瓷，在10度－130度的2θ扫描角范围内，在室温下进行粉末X射线衍射。测定结果显示，高温合成的Ca2KN2(PO4)2晶体相是α－CaKPO4和α－CaNaPO4晶体的高温固溶体，呈六方晶体结构，晶格参数为：α0＝0．54396nm,C0=0.72976nm，晶胞体积V＝0．187nm^3.     

Crystal Structures of Dy_2(WO_4)_3 and GdY(WO_4)_3

Two compounds, Dy2(WO4)3 and GdY(WO4)3, were synthesized by using the standard solid state reaction technique. The crystal structure was determined by powder X-ray diffraction and Rietveld refinement method. It is found that both compounds have Eu2(WO4)3-type monoclinic structure, with space group C 2/c, Z = 4. The unit cell parameters of Dy2(WO4)3 are a = 0.75981(1) nm. b = 1.13220( 1) nm, c = 1.13254( 1) nm, and β= 109.8001(3)°, and those of GdY(WO4)3 are a = 0.76175(1) nm, b = 1.13543(1) nm, c = 1.13496(2) nm, and bbbbbbbbbβwhile each rare-earth atom is surrounded by eight oxygen atoms. WO4 tetrahedra share their four vertices with REO8 (RE = Dy, Gd, or Y) trigondodecahedra and some REO8 trigondodecahedra share an edge with each other. The phase transition and the magnetic properties were investigated by differential thermal analysis (DTA) and dc superconducting quantum interference device (SQUID) magnetometer.     

急冷烧结法制备六钛酸钾晶须的工艺研究

以分析纯K2CO3和工业纯TiO2为原料,采用急冷烧结法制备了六钛酸钾晶须,利用扫描电镜、X射线衍射仪等手段,研究了二次保温时间和钛源化合物类型等对其形貌及物相的影响.结果表明:以金红石型二氧化钛为钛源,TiO2/K2CO3的摩尔比为5.5∶1时,1200℃保温3h,然后在高于1114℃二次保温2h,再经急冷后进行解离、抽滤和烘干,即可得到分散性好、物相纯度较高的六钛酸钾晶须.     

Substrate Temperature-Dependent Physical Properties of Thermally Evaporated Sn_4Sb_6S_(13)Thin Films

In this work,the homogenous thin films of sulfosalt Sn_4Sb_6S_(13) were successfully synthesized by the thermal evaporation technique onto corning 7059 glass substrates heated at various temperatures in the range of 30-200 ℃.The surface morphology and structural characteristics of Sn_4Sb_6S_(13) films were analyzed by atomic force microscopy,X-ray diffraction,and energy-dispersive X-ray,respectively.The X-ray diffraction analysis revealed that Sn_4Sb_6S_(13) thin films crystallized in monoclinic structure according to a preferential direction(6 11).An improvement in the structural properties by increasing the substrate temperature was observed.The values of some important parameters such as absorption coefficient(α),band gap(E_g),refractive index(n),extinction coefficient(k),and dielectric constant(ε_∞) of thin film were determined.The absorption coefficient was larger than 10~5 cm~(-1) in the visible range.The electron transition of Sn_4Sb_6S_(13)films was direct allowed with the values that decreased(2-1.69 eV) by increasing substrate temperature from 30 to 200 ℃.The dispersion data obeyed the single oscillator relation of the Wemple-DiDomenico model and Cauchy model.The electrical free carrier susceptibility and the carrier concentration of the effective mass ratio were estimated according to the model of Spitzer and Fan.     

Experimental Determination and Atomistic Simulation on the Structure of FeZn<Subscript>13</Subscript>

By X-ray diffraction combined with Rietveld structure refinement, the crystal structure of FeZn₁₃ was determined experimentally in this study. The results indicated that the structure of FeZn₁₃ is monoclinic and the lattice parameters are a = 1.3408 nm, b = 0.7605 nm, c = 0.5074 nm, and β = 127.206°. It was confirmed that Fe atoms occupy the 2c position (0, 0, 0.5) in space group C2/m, and the coordinates of Zn atoms at the Zn(1) position are (0.114, 0.5, 0.293), which supports the results from Belin et al. (Acta Cryst. C 56:267, 2000). In addition, an atomistic calculation was carried out to determine the crystal structure based on the interatomic potentials obtained using the lattice inversion method, and Fe atoms are substituted by Zn atoms in the narrow solubility range of FeZn₁₃, which is the fundamental for studying the solubility and site preference of alloying elements of FeZn₁₃. Good agreement between the experimental results and the theoretical calculations was achieved.     

钛合金表面原位生成钛酸钾生物陶瓷涂层的制备及其生物相容性

采用原位干混合煅烧合成法在钛合金基体上成功制备了K2Ti6O13涂层，并对涂层的微观形貌、相组成、涂层-基体的结合强度进行了研究，通过模拟体液实验对其生物活性进行了评估。结果表明，涂层与基体间结合牢固，能够经受空冷条件下的冷热冲击，热膨胀系数的良好匹配是结合强度提高的主要原因。涂层粗糙的表面和气孔可为骨的向内生长提供有利位置。经模拟体液浸泡，涂层表面形成了钙磷比接近人体骨骼的钙磷层，表明涂层具有良好的生物活性。     

New Zr6CoAs2-type R6MnSb2 and R6MnBi2 compounds (R=Y, Lu, Dy, Ho)

A powder X-ray diffraction investigation of the new ternary compounds Zr₆CoAs₂-type R₆MnSb₂ and R₆MnBi₂ (R=Y, Lu, Dy, Ho) is reported. The compounds Ho₆MnSb₂ (a=0.8070(2) nm, c=0.4230(1) nm), Lu₆MnSb₂ (a=0.7930(1) nm, c=0.4173(1) nm), Y₆MnBi₂ (a=0.8242(1) nm, c=0.4292(1) nm), Dy₆MnBi₂ (a=0.8211(1) nm, c=0.4286(1) nm), Ho₆MnBi₂ (a=0.8164(1) nm, c=0.4250(1) nm) and Lu₆MnBi₂ (a=0.8019(2) nm, c=0.4185(1) nm) crystallize in the hexagonal Zr₆CoAs₂-type structure (space group P6b2m No. 189). The Zr₆CoAs₂-type structure is a superstructure of the Fe₂P-type structure.