Pd-Y合金膜的MOCVD研制

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

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 Al2 O3 衬底上成功制备了超薄钯钇合金膜 .用 Pd( Ac Ac) 2 +Y( Ac Ac) 3 混合源制备的钯钇合金膜的晶粒尺寸 ( 2 1nm× 10 nm )比单独用 Pd( Ac Ac) 2 制备的钯膜的尺寸 ( 3 0 nm× 10 nm )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 2 0 0～ 3 5 0℃范围内渗透率稳定 .

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.