Deposition and characterization of YBCO/CeO2/YSZ/CeO2 multilayers on biaxially textured Ni substrates

CeO2/YSZ/CeO2 buffer layers were deposited on biaxially textured Ni substrates by pulsed laser deposition. The influence of the processing parameters on the texture development of the seed layer CeO2 was investigated. Epitaxial films of YBCO were then grown in situ on the CeO2/YSZ （yttria-stabilized ZrO2）/CeO2-buffered Ni substrates. The resulting YBCO conductors exhibited self-fleld critical current density Jc of more than 1 MA/cm^2 at 77K and superconducting transition temperature Tc of about 91K.

Improvement of Surface Morphology of Yttrium-Stabilized Zirconia Films Deposited by Pulsed Laser Deposition on Rolling Assisted Biaxially Textured Substrate Tapes

The surface morphology of buffer layer yttrium-stabilized zirconia （YSZ） of YBa2CuaO7-σ （YBCO） high temperature superconducting films relies on a series of controllable experimental parameters. In this work, we focus on the influence of pulsed laser frequency and target crystalline type on surface morphology of YSZ films deposited by pulsed laser deposition （PLD） on rolling assisted biaxially textured substrate tapes. Usually two kinds of particles are observed in the YSZ layer： randomly distributed ones on the whole film and self-assembled ones along grain boundaries. SEM images are used to prove that particles can be partly removed when choosing dense targets of single crystalline. Lower frequency of pulsed laser also contributes to a smoother film surface. TEM images are used to view the crystalline structure of thin film. Thus we can obtain a basic understanding of how to prepare a particle-free YSZ buffer layer for YBCO in optimized conditions using PLD. The YBCO layer with nice structure and critical current density of around 5 MA/cm2 can be reached on smooth YSZ samples.

Effect of steady shear on multi-axial texture of symmetric diblock copolymers

The effect of steady shear on multi-axial texture of symmetric diblock copolymer was investigated by using dynamic density functional theory.Through modifying the periodic boundary condition,the parallel-transverse biaxial texture and perpendicular-parallel-transverse triaxial texture have been observed.In the formation of the multi-axial texture,there are two critical velocities uper-par and upartra,at which the transition between the perpendicular and the parallel lamellar morphology,and the transition between the parallel and the transverse lamellar morphology occur,respectively.The two critical velocities increase as the inter-action parameter increases,but they almost remain constant at different shear rates.Furthermore,the rotation from the transverse lamellae to the parallel lamellae induced by the shear strain,and the increase of lamellar spacings of the three lamellae after removing the shear,have also been observed by the time evolution of the morphologies.These phenomena are consistent with experimental work.