Determination of film thicknesses of metal oxides prepared by atomic layer deposition on SBA-15
Determination of film thicknesses of metal oxides prepared by atomic layer deposition on SBA-15
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DOI：
10.1016/j.micromeso.2023.112945
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发表时间：
2023-12
影响因子：
5.2
通讯作者：
Ching-Yu Wang;Benjamin T. Ferko;Kai Shen;K. Winey;J. Vohs;R. Gorte
中科院分区：
文献类型：
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作者：
Ching-Yu Wang;Benjamin T. Ferko;Kai Shen;K. Winey;J. Vohs;R. Gorte
采用原子层沉积法（ALD）在SBA-15中制备了ZrO 2和CeO 2薄膜，负载量为0.92 g氧化物/g SBA-15。扫描透射电子显微镜（STEM）与能量色散谱（EDS）表明，氧化物均匀生长的中孔内。然后使用三种方法分析作为ALD循环次数的函数的膜厚度：1）假定膜的堆积密度的质量变化; 2）来自具有N2吸附等温线的Barret-Joyner-Halenda（BJH）分析的孔径变化;和3）小角X射线散射（SAXS）。假定堆积密度的膜厚度比从BJH分析获得的膜厚度小6至8倍。SAXS分析给出的膜厚度约为从堆积密度获得的膜厚度的两倍。这些方法之间的差异可能的解释进行了讨论。
ZrO2and CeO2films were grown in SBA-15 by Atomic Layer Deposition (ALD) to loadings of 0.92 g oxide/g SBA-15. Scanning Transmission Electron Microscopy (STEM) with Energy Dispersive Spectra (EDS) showed that the oxides grew uniformly inside the mesopores. Film thicknesses were then analyzed as a function of the number of ALD cycles using three methods: 1) mass changes assuming bulk densities for the films; 2) changes in pore size from Barret-Joyner-Halenda (BJH) analysis with N2adsorption isotherms; and 3) small-angle X-ray scattering (SAXS). Film thicknesses assuming bulk densities were between 6 and 8 times smaller than those obtained from BJH analysis. SAXS analysis gave film thicknesses that were approximately twice that obtained from bulk densities. Possible explanations of the discrepancies between these methods are discussed.