Structural characterization of nanoporous Pd films grown via ballistic deposition
Structural characterization of nanoporous Pd films grown via ballistic deposition
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DOI：
10.1016/j.susc.2005.05.008
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发表时间：
2005-07-20
期刊：
影响因子：
1.9
通讯作者：
Kay, BD
中科院分区：
文献类型：
--
作者：
Kim, J;Dohnálek, Z;Kay, BD
在22 K和不同剂量角下气相沉积纳米多孔钯膜在氧化Mo（i00）衬底上。采用程序升温解吸法（TPD）测定了在22 K下沉积和退火后的Pd膜的表面积。发现钯膜的表面积与钯的投加角度和退火温度有显著的关系。在22 K条件下，以85°沉积角生长的Pd膜的最大表面积为120 m(2)/g。非原位扫描电镜成像显示，这些薄膜由倾斜排列的纳米晶细丝组成。退火研究表明，薄膜在退火过程中变得致密，在300 K时损失了约50%的表面积，在500 K时几乎完全致密。与在22 K下生长的Pd膜相比，在高温下（< 300 K）沉积Pd膜产生的密度更大。生长在300k以上会导致Pd从衬底上脱湿。(c) 2005 Elsevier B.V.版权所有
Nanoporous Pd films were vapor-deposited onto an oxidized Mo(I 00) substrate at 22 K and various dosing angles. Temperature programmed desorption (TPD) of N-2 was used to determine the surface area of the Pd films immediately after deposition at 22 K, and following annealing. The surface area of Pd films was found to depend dramatically on the Pd dosing angle and annealing temperature. Pd films grown at 22 K with a 85 degrees deposition angle exhibit the highest surface area of 120 m(2)/g. Ex situ SEM imaging reveals that these films consist of a tilted array of nanocrystalline filaments. The annealing studies show that the films densify upon annealing and lose approximately 50% of their surface area by 300 K and are almost completely dense by 500 K. Pd deposition at elevated temperatures (< 300 K) produces denser Pd films compared to those grown at 22 K. Growth above 300 K leads to dewetting of Pd from the substrate. (c) 2005 Elsevier B.V. All rights reserved.