The electron attenuation length is a material property, which defines the probing depth of all electron spectroscopies. For kinetic energies below 50 eV, very few data exist in the literature, although this energy range is vital for electron spectroscopy using low-energy electrons, e.g., for studying the valence electronic band structure. Extremely short attenuation lengths are expected for the transition metals gadolinium and terbium. To determine the electron attenuation length in these materials, we conducted inverse-photoemission overlayer experiments with ultrathin Gd and Tb films on W(110). For 10-eV electrons, we find an attenuation length of about one monolayer in Gd and even less in Tb, i.e., two thirds (or more) of the electrons are stopped by only one monolayer. These results imply extremely short information depths for electron spectroscopies with low energies on the lanthanides Gd and Tb.

中文翻译：

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Gd和Tb中低能电子的单层衰减长度

电子衰减长度是一种材料特性，它定义了所有电子光谱的探测深度。对于低于50 eV的动能，文献中几乎没有数据，尽管该能量范围对于使用低能电子的电子光谱至关重要，例如，用于研究价电子能带结构。过渡金属g和ter的衰减长度极短。为了确定这些材料中的电子衰减长度，我们对W（110）上的超薄Gd和Tb膜进行了反光发射覆盖实验。对于10 eV电子，我们发现衰减长度在Gd中约为一个单层，而在Tb中则更短，即三分之二（或更多）的电子仅被一个单层阻止。