以乙酰丙酮铱为前驱体,采用金属有机化合物化学气相沉积(MOCVD)技术在石英片上沉积了Ir/C簇膜。研究了氧气流量及沉积温度对Ir/C簇膜成分和结构的影响。研究发现,少量氧气的加入(4mL/min)大幅度地降低了Ir/C簇膜中碳元素的含量;沉积温度对薄膜中碳含量的影响规律则比较复杂:未通氧气的情况下,在实验温度范围内碳含量随着温度的升高而增大,而在通入氧气的情况下碳含量呈现出先升后降的复杂变化趋势。大量碳的沉积宽化了Ir的衍射峰,使其具有非晶衍射的特征。当沉积温度为650℃,未通氧气沉积的Ir/C簇膜中铱晶粒粒经约为3nm。
Ir/C cluster films were prepared by MOCVD (metal-organic chemical vapor deposition) on quartz plate substrates using iridium-acetylacetonate as the precursor. The effects of oxygen flow and deposition temperature on the composition and microstructure of Ir/C cluster films were studied. It was found that small amount of oxygen additions (4mL/min) to the source gas decreases drastically the carbon content of the films. The effects of deposition temperature on carbon content in Ir/C cluster films are related to the oxygen flow: the carbon content increases with increasing in deposition temperature in the films prepared without oxygen addition and increases first and then decreases with increasing in deposition temperature in the films prepared with some oxygen addition. The Ir/C films with higher carbon content showed wider and lower XRD spectrum of iridium peaks, which was the characteristic of diffraction spectrum of non-crystalline. Ir grains are about 3nm in diameter as deposited at 650℃ without oxygen addition.