Fabrication of IBAD-MgO and PLD-CeO2 Layers for YBCO Coated Conductors

MgO thin films with different textures are fabricated by the ion beam assisted （IBAD） method on the Y2O3/Al2O3 buffered C276 tape. Then a CaO2 layer is directly grown on the IBAD-MgO film by the pulsed laser deposition （PLD） method. Effects of lBAD-MgO texture, substrata temperature and thickness on the grain alignment of the CeO2 layer are investigated. Film characterization is performed by x-ray diffraction and atomic force microscopy. It is found that the orientation and texture degree of the CaO2 layer are very sensitive to the IBAD-MgO texture. By optimizing the IBAD-MgO texture, CeO2 has pure （002） orientation and excellent biaxial texture deposited in a broad substrata temperature range. In addition, the PLD-CeO2 layer has a thickness effect. Under the optimized experimental condition, the PLD-CeO2 layer has a high in-plane texture of △φ = 2.9° and a smooth surface with an rms surface roughness of less than 2nm. The critical current density Jc of a 0.4μm-thick YBCO film deposited on the CeO2 layer is 6.25 × 106 A/cm2 at 77K and a self-field.

Phase Formation and Process Analysis of SiC-Al_2O_3-Al_6Si_2O_(13) Composite Powder via Carbothermal Reduction of Fly Ash at 1 550 ℃

Silicon carbide（SiC）-alumina（Al_2O_3）-mullite（Al_6Si_2O_（13）） composite powder was successfully synthesized at 1 550 ℃ for 5 h via carbothermal reduction reaction,and the effects of various mass ratios of active carbon to fly ash（0.38,0.44 and 0.58） on the phase composition and microstructure of products were investigated,and the formation process of the powder was also analyzed in detail.The products mainly consist ofβ-SiC,α-Al_2O_3,Al_6Si_2O_（13） and FeSi.Increasing carbon content favors the decomposition of Al_6Si_2O_（13） and formation of SiC.The average particle size of β-SiC andα-Al_2O_3 is about 1 μm and that of Al_6Si_2O_（13） is 5-10μm.The formation process of SiC-Al_2O_3-Al_6Si_2O_（13）powder includes the decomposition of mullite in fly ash and formation of SiC.

Optical property of an antireflection coating fabricated by an optimal spin-coating method with a pH-modified SiO2 nanoparticle solution

An antireflection （AR） coating is fabricated by applying an optimal spin-coating method and a pH-modified SiO2 nanoparticle solution on a cover glass. Because the pH value of the solution will affect the aggregation and dispersion of the SiO2 particles, the transmittance of the AR-treated cover glass will be enhanced under optimal fabricated conditions. The experimental results show that an AR coating fabricated by an SiO2 nano- particle solution of pH 11 enhances the transmittance approximately by 3% and 5% under normal and oblique incident conditions, respectively. Furthermore, the AR-treated cover glass exhibits hydrophobicity and shows a 65% enhancement at a contact angle to bare glass.

Fast-growing procedure for perovskite films in planar heterojunction perovskite solar cells

A fast-growing procedure（FGP） to fabricate perovskite films with large grain sizes is described in this article. In the FGP method, the perovskite precursor solution is coated onto the substrates at a temperature of 240 8C. The solvent in the precursor solution evaporates quickly in about 2 s, resulting in the rapid formation of a perovskite film without further annealing process. Millimeter-scale perovskite grain clusters are obtained in the film. Based on such perovskite films, fabricated planar heterojunction perovskite solar cells give a power conversion efficiency（PCE） above 8%.

Morphology-controlled synthesis of Al/Fe_2O_3 nano-composites via electrospinning

In this article, nano-scale Al/Fe2O3 composites with different morphologies were successfully obtained by a simple electrospinning technique, which is based on a surfactant（polyvinyl pyridine, PVP） in a mixture of N,N-dimethylformamide（DMF） and 2-propanol. The electrospun Al/Fe2O3 composites exhibited a crystal structure and phase composition by X-ray diffraction analysis. The different morphologies of the Al/Fe2O3 composites were also observed through scanning electron microscopy and transmission electron microscopy. It was found that the rather simple electrospinning method used to prepare the morphology-controlled Al/Fe2O3 composites may have the potential for preparation of propellants, explosives, and pyrotechnics in the future.