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.
In-situ epitaxial growth study of Bi/sub 2/(Sr,Ca)/sub 3/Cu/sub 2/O/sub x/ films by ion beam sputtering on cleaved MgO substrates
In-situ epitaxial growth of Bi/sub 2/(Sr/sub 0.6/Ca/sub 0.4/)/sub 3/Cu/sub 2/O/sub x/ films on cleaved MgO substrates was studied by ion beam sputtering. The crystallographic structures were analyzed by using in-situ reflection high-energy electron diffraction, a four-circle X-ray diffractometer, and a scanning electron microscope. While the epitaxial films on polished MgO substrates commonly showed the fourfold symmetry, the epitaxial films having the twofold symmetry were successfully grown on the cleaved MgO substrates, and the films contained two types of misoriented domains. The epitaxial relationship between these domains and then cleaved MgO substrates was such that the b-axis of each domain deviated approximately +or-13 degrees from