Pd-Y合金膜的MOCVD研制

采用金属有机化合物的化学气相淀积法,以β-二酮螯合物为源物质,在多孔Al₂O₃衬底上成功制备了超薄钯钇合金膜.用Pd(AcAc)₂+Y(AcAc)₃混合源制备的钯钇合金膜的晶粒尺寸(21nm×10nm)比单独用Pd(AcAc)₂制备的钯膜的尺寸(30nm×10nm)小.XPS研究发现,制备的Pd-Y合金膜中Y/Pd比小于源物质的.氢的透气性实验表明,合金膜的氢渗透率高于Pd膜,且在200～350℃范围内渗透率稳定.

Preparation of Pd-Y Alloy Membranes on Porous Alumina by MOCVD Using Mixed Metal β-Diketone as Precursors

A metal-organic chemical vapor deposition (MOCVD) process with metal β-diketone as precursor was applied to preparing Pd and Pd-Y alloy composite membranes on porous alumina substrates. A palladium phase membrane consisting of primary crystallites with dimension of around 30 nm×10 nm was deposited when a single Pd(AcAc)₂ precursor was used. With a mixed precursor of 8Pd(AcAc)₂+Y(AcAc)₃, uniform and dense Pd-Y alloy membranes were reproducibly formed. The alloy membranes consisted of primary crystallites with a dimension of 21 nm×10 nm , which is much smaller than that of pure Pd membranes. XPS studies revealed that the content of Y in the Pd-Y alloy membranes was less than that in the mixed precursor. This goes along with the results of thermal gravimetric analysis of metal β-diketones, which showed that the volatility of Y(AcAc)₃ was lower than that of Pd(AcAc)₂. Hydrogen testing showes that the flux of a Pd-Y alloy membrane is much higher than that of a Pd membrane at the temperature investigated. And Pd-Y alloy membranes were more stable than Pd membranes.