Phase diagram of the pseudobinary system Bi–Co–O

Samples with different ratios of Bi₂O₃ and Co₂O₃ were prepared by ceramic route. Based on the results of differential thermal analysis, X-ray powder diffraction, SEM–EDXA and FactSage database the phase diagram of the Bi–Co–O diagram in air atmosphere was assessed and calculated using the FactSage software. The sillenite structure of Bi₂₄Co₂O₃₉ was identified and the single phase homogeneity range of Bi₂₄Bi_2?xCo_xO₃₉, x = 0.9–2.0 was determined by Rietveld analysis and SEM–EDXA. To verify the composition in the various parts of the phase diagram at elevated temperatures, a number of high-temperature annealing experiments was performed followed by rapid quenching to room temperature.     

Effects of rapid thermal annealing treatment on 0·95(Na0·5Bi0·5)TiO3-0·05BaTiO3 thin films

Abstract

Abstract

A 0·95(Na_0·5Bi_0·5)TiO₃-0·05BaTiO₃+1?wt-%Bi₂O₃ (NBT-BT3) ceramic was used as target to deposit the NBT-BT3 thin films. The excess 1?wt-%Bi₂O₃ was used to compensate the vapourisation of Bi₂O₃ during the depositing processes. The optimal deposition parameters were substrate temperature of 500°C, radio frequency power of 100?W, chamber pressure of 10?mtorr and oxygen concentration of 40%. Rapid thermal annealing treated processes were carried out on NBT-BT3 thin films from 600 to 800°C in ambient or in oxygen atmosphere for 1?min. The surface morphologies and thicknesses of NBT-BT3 thin films were characterised by field emission scanning electron microscopy, and the thickness was ～216?nm. It would be shown that the NBT-BT3 thin films annealed in oxygen atmosphere had the smaller grain size, larger memory window, smaller leakage current density, larger remanent and saturation polarisation and smaller coercive field than the NBT-BT3 thin films annealed in ambient atmosphere.     

Optimization of dielectric constant temperature coefficient of pyrochlores containing bismuth

1　INTRODUCTIONDielectric ceramics are widely used with ad vances in microelectronic technologies. Bismuth based pyrochlores exhibit well known high fre quency dielectric properties for multilayer capaci tor. Group of pyrochlore structured compounds isof general formula A2B2O7(where A is trivalent orbivalent cations and B is quadrivalent and quinque valent cations). As a member of the pyrochlorefamily of compound, bismuth zinc niobate is a typi cal high frequenc…     

Design of a defect-induced orange persistent luminescence phosphor BaZnGeO4:Bi3+

We report a novel bright orange persistent luminescence (PersL) phosphor BaZnGeO₄:Bi³⁺ with broad emission and PersL spectra. Its crystal structure, photoluminescence (PL) spectra, thermoluminescence (TL) spectra and PersL spectra were investigated in detail. The two emission bands at 440 nm and 595 nm originate from Bi³⁺ ions in normal Ba²⁺ sites (Bi1) and Ba²⁺ sites close to vacancy defects (Bi2), respectively. The introduction of and defects improves the emission intensity of Bi2 more than that of Bi1, demonstrating that Bi2 is related to the vacancy defects. The orange emission and PersL properties of BZGO:Bi³⁺ can be improved when a little and defects are introduced, because the introduction of and defects makes it easier for Bi³⁺ to enter in Ba²⁺ sites; and for PersL, and defects can perform as the effective trap centers to capture more charges, which is beneficial for PersL. BZGO:Bi³⁺ has quite good thermal stability, and the bright orange PersL can be observed by the naked eye for 1 h. Finally, a feasible PersL mechanism of BZGO:Bi³⁺ was proposed to clarify the PersL-generation process.     

g-C3N4/Bi/Bi2WO6光催化材料的协同改性研究

以五水合硝酸铋[Bi（NO₃）₃·5H₂O]为铋源、二水合钨酸钠（Na₂WO₄·2H₂O）为钨源通过水热法制备出多孔钨酸铋（Bi₂WO₆）,并以纳米板条堆叠形成椭球结构的类石墨相氮化碳（g-C₃N₄）为基底通过溶剂热法在原位还原金属铋（Bi）的同时制备出具有Z型异质结构的g-C₃N₄/Bi/Bi₂WO₆（CN/B/BWO）复合光催化材料。采用X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）、氮气吸附-脱附等温线（BET）、紫外-可见吸收光谱（UV-Vis）和光致发光（PL）光谱等检测手段对制备的样品进行了表征。结果表明,金属铋可以作为类石墨相氮化碳和钨酸铋之间的电荷转移媒介,其产生的表面等离子体共振（SPR）效应可协同增强光生电子-空穴对的分离效率和载流子的迁移率,从而提升样品的光催化活性。采用350 W氙灯照射30 min,样品CN/B/BWO-0.7对盐酸四环素（TC-H）的降解率达到99.94%,并对其降解机理进行了探讨。     

热蒸发法制备金属碲纳米线

在真空管式炉内,以Bi2Te3为蒸发源,在蒸发温度560 ℃,保温时间2h条件下,采用热蒸发法在涂有Au溶胶的石英基片上制备出了大量碲纳米线。通过XRD、SEM、HRTEM等仪器对碲纳米线的组织结构和微观形貌进行了表征与分析。结果表明,制备出的碲纳米线为沿（101）方向取向生长的三方单晶碲纳米线,直径范围在40~100nm之间,生长机制符合VLS生长机制。蒸发源材料和Au溶胶是热蒸发法制备碲纳米线的关键因素。     

Separation of As and Bi and enrichment of As,Cu, and Zn from copper dust using an oxidation-leaching approach

Copper dust with high arsenic content is a hazardous waste that should be treated properly. Herein, the copper dust is oxidized, leached, and separated at room temperature and atmospheric pressure. To separate As and Bi, part of As(Ⅲ) in copper dust is oxidized to As(V), so that most of the As, Cu, and Zn elements enter the solution and the Bi remains in the leaching residue. Also, the influence of several factors,such as H_2 SO_4 dosage, H_2 O_2 dosage, liquid–solid ratio, leaching temperature and leaching time, on the leaching percentage of As, Bi, Cu, and Zn is systematically investigated. The optimal conditions are obtained as follows: liquid–solid ratio of 3:1, H_2 O_2 dosage of 10 ml/50 g(dust), H_2 SO_4 dosage of4.5 ml/50 g(dust), leaching temperature of 85 °C, and leaching time of 3 h. Under these conditions,the leaching percentage of As, Cu, Zn, and Bi is found to be 97.39%, 96.11%, 97.32%, and 2.40%, respectively. For further recovery of As from the leaching solution, the one-step recycle leaching of the leaching solution is performed to increase the concentration of As in the recycled leaching solution. The concentration of arsenic in the recycling leaching solution is found to be 79.63 g·L~(–1), which is beneficial for the study on further recovery of As_2 O_3.     

Influence of rapid solidification on Sn–8Zn–3Bi alloy characteristics and microstructural evolution of solder/Cu joints during elevated temperature aging

The effects of rapid solidification on the microstructure and melting behavior of the Sn–8Zn–3Bi alloy were studied. The evolution of the microstructural characteristics of the solder/Cu joint after an isothermal aging at 150 °C was also analyzed to evaluate the interconnect reliability. Results showed that the Bi in Sn–8Zn–3Bi solder alloy completely dissolved in the Sn matrix with a dendritic structure after rapid solidification. Compared with as-solidified Sn–8Zn–3Bi solder alloy, the melting temperature of the rapid solidified alloy rose to close to that of the Sn–Zn eutectic alloy due to the extreme dissolution of Bi in Sn matrix. Meanwhile, the adverse effect on melting behavior due to Bi addition was decreased significantly. The interfacial intermetallic compound (IMC) layer of the solder/Cu joint was more compact and uniform. Rapid solidification process obviously depressed the formation and growth of the interfacial IMC during the high-temperature aging and improved the high-temperature stability of the Sn–8Zn–3Bi solder/Cu joint.     

Polarographic behavior of 1,4,7-triazacycloanane-N,N'''',N"-tris (meth-ylphonic acid) (NOTP)-Bi(Ⅲ) complex

The polargraphic behavior of Bi(III)-NOTP complex has been investigated in aqueous solution. It was found thatunder the conditions of pH 3.0 and of 0.02 mol/L NH4Cl, the Bi(III)-NOTP system gives a sensitive second order derivativewave at -0.340 V(vs SCE), which is proved to be an adsorptive complex wave. The composition of the complex isBi(III):NOTP. Furthermore, the peak current is linear to the concentration of Bi(III) in the range from 3.0×10-8 to 5.0×10-6mol/L. Artificial and practical samples have been detected with high sensitivity and receptivity.     

插入Bi层对NiFe/Cu/NiFe/FeMn自旋阀多层膜交换耦合的影响

对于NiFe/Cu/NiFe/FeMn自旋阀多层膜，Cu原子偏聚到NiFe/FeMn界面将导致自旋阀多层膜中NiFe/FeMn的交换耦合Hex下降，然而，少量的表面活化原子Bi被沉积到Cu层和被钉扎NiFe层之间。Cu原子在NiFe/FeMn界面的偏聚可以被抑制。而且，更重要的是Ta/NiFe/Cu/NiFe/FeMn/Ta自旋阀多层膜中的交换耦合场Hex可以被有效地提高。