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

以钙、铜、锶的β-二酮化合物和铋的有机金属化合物为原料，采用MOCVD方法制备了超导薄膜和超细颗粒。以Ar气体为载气，将蒸发后的原料引入反应室。作为氧化剂的O2气体同时通过不同的途径进入反应室。在不同的蒸气浓度、反应温度和反应器内的操作压力下，用电子显微镜观察了反应器壁上形成的薄膜和沉积的颗粒。研究发现，较高的水蒸气浓度、较高的反应温度和较高的压力对薄膜的生成有促进作用，而较低的压力对薄膜的形成有较大的促进作用。观测到的趋势与数值求解气溶胶动力学方程得到的模拟结果定性地吻合，其中颗粒的形成由简化的反应和凝聚模型来评估。

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.