The composition and structure of Pd-Au surfaces.
The composition and structure of Pd-Au surfaces.
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DOI：
10.1021/jp053515r
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发表时间：
2005-09
期刊：
影响因子：
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通讯作者：
C. Yi;K. Luo;T. Wei;D. Goodman
中科院分区：
文献类型：
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作者：
C. Yi;K. Luo;T. Wei;D. Goodman
用物理气相沉积法在Mo(110)衬底上沉积了Pd、Au和Pd-Au混合物，并用低能离子散射光谱(Leiss)、红外吸收光谱(IRAS)、程序升温脱附(TPD)和X射线光电子能谱(XPS)测定了Pd-Au混合物的表面浓度和形貌。Pd-Au混合物在700-1000K之间形成一种稳定的合金，与主体成分相比，Au具有相当大的丰度。在800K下对1：1Pd-Au混合物进行热处理，形成了Au(0.8)Pd(0.2)组分的表面合金，其中Pd主要被Au包围。通过改变Pd-Au合金的体相浓度，可以系统地控制这个孤立的Pd位的表面浓度。
Pd, Au, and Pd-Au mixtures were deposited via physical vapor deposition onto a Mo(110) substrate, and the surface concentration and morphology of the Pd-Au mixtures were determined by low-energy ion scattering spectroscopy (LEISS), infrared absorption spectroscopy (IRAS), temperature-programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). Pd-Au mixtures form a stable alloy between 700 and 1000 K with substantial enrichment in Au compared to the bulk composition. Annealing a 1:1 Pd-Au mixture at 800 K leads to the formation of a surface alloy with a composition Au(0.8)Pd(0.2) where Pd is predominantly surrounded by Au. The surface concentration of this isolated Pd site can be systematically controlled by altering the bulk Pd-Au alloy concentration.