Control of Preparation of Superconductive Bi-Ca-Sr-Cu-O Thin Film and Fine Particles by CVD.

点击翻译按钮获取中文摘要

The formation of superconductive Bi-Ca-Sr-Cu-O thin film and fine particles was carried out using beta-diketonate complexes of Ca, Cu and Sr and organometallic compound of Bi as starting materials in MOCVD method. The vaporized starting materials were introduced into the reaction chamber using Ar gas as a carrier gas. O_2 gas acting as an oxidizing agent was introduced to the reaction chamber at the same time through a different path. The thin films formed and the particles deposited on the reactor wall were observed using an electron microscope under various supplied concentrations of vapor, reaction temperatures and operating pressure inside the reactor. It has been found that the generation of fine particles is enhanced at higher concentration of vapor, higher reaction temperature and higher pressure, but the formation of thin films is more enhanced under lower pressure. The observed trends agreed qualitatively with the simulation results obtained by numerically solving the aerosol dynamic equation where the particle formation was evaluated by a simplified reaction and coagulation model.