Study on the growth mechanism of Bi-2212 ribbon-like thin films on flat Ag substrate by the atomization technique
The growth mechanism of Bi-2212 ribbon-like thin films on flat Ag substrate using an atomization technique was studied. The fine Bi-2212 powders were dispersed on the Ag substrate before the melting process, so as to avoid the change in the composition of the molten phase with distance, which would result in the formation of the impurity phases. Nearly reversible peritectic reaction on cooling causes the formation of well-defined Bi-2212 phase. Based on the results of in situ high temperature microscope observation, the wetting of the molten phase to the growing ribbons was identified as the essential condition for the growth of the ribbon-like thin films.
Preparation and superconducting properties of extremely thin Bi2Sr2Ca1Cu2Ox ribbon-like films on silver substrates
Abstract We have developed a simple technique for growing ribbon-like single crystalline films of Bi-2212 on Ag substrates. The process is performed under ambient pressure only by heating the Bi-2212 pellet on the edge of the substrates. The ribbons are extremely thin and stuck firmly to the substrates, resulting in the formation of a new type of composite of Bi-2212 ribbons/Ag. The ribbon-like films showed the superconducting transition with the onset temperature of ∼80 K.
Superconducting properties of Bi2Sr2CaCu2Oy/Bi2Sr2CuOx multilayer thin films
Abstract We have prepared Bi 2 Sr 2 CaCu 2 O y (BSCCO)/Bi 2 Sr 2 CuO x (BSCO) multilayer thin films using a multitarget RF magnetron sputtering technique. Our BSCO films exhibit a semiconductor-like transport property, and BSCCO/BSCO multilayers are supposed as superconductor/nonsuperconductor multilayers. The x-ray diffraction measurements showed that all of the multilayers with various thicknesses have the c-axis normal to the substrate surface. In the multilayer films with the constant BSCO layer thickness of 100A, an T c onset slightly decreases from 85 K to 75 K with decreasing the BSCCO layer thickness from 250A to 31A. From this result it seems that interlayer coupling in BSCCO/BSCO multilayers is weaker than in YBaCuO/PrBaCuO multilayers.