Sm/Ni模型催化剂的研究I.Sm膜及Sm/Ni表面合金的生成和结构

The Investigation of Sm/Ni Model Catalysts :I. Formation and Structure of Sm Overlayer and Sm/Ni Surface Alloys on Nickel Surface

用AES考察了多晶Ni表面上Sm膜及Sm/Ni表面合金的生成条件和构成.室温下,Sm膜在多晶Ni表面上的生长符合S-K模式.热处理温度对表面构成有强烈影响,在300-700K间发生了亚稳态Sm膜的稳定化和金属间相互扩散;而在700-1000K,表面组成不再发生变化,显示表面合金的生成.表面合金的组成和Sm的起始厚度及热处理条件有关.AES深度剖析及氢吸附实验为表面的构成提供了有力证据.对表面膜的生成机理进行了讨论.

The growth and structure of Sm overlayer and Sm/Ni intermetallic phases on polycrystalline Ni surface have been investigated by AES. The growth of Sm film appears following the Strans-ki-Krastanov mode at 300 K. Annealing at 700-1000 K leads to formation of the Sm/Ni surface alloys. The composition and structure of the surface alloy depend on the initial Sm loading and subsequent temperature of heating. The AES depth profiling measurements and hydrogen adsorption provede evidence for the formation and structure of surface alloys.