Surface Compound Formation in Be Adsorption on W(100): Absolute Concentration and Properties

Be adsorption at T = 900–1100 K results in formation of a stable adsorption state; it drops the activation energy of atomic Be dissolution in the substrate bulk, and all newly deposited Be dissolves in the substrate. The absolute concentration of atomic Be in this state has been measured by Auger electron spectroscopy using specially designed ultra high vacuum getter Be source. The concentration is (1.0 ± 0.1) × 1015 sm–2 and corresponds to WBe stoichiometry relative to W surface concentration. The layer is destroyed at T > 1100 K, the atomic Be dissolves in the bulk with the activation energy ∼3.5 eV.