Enrichment depth profiles in polymer blends measured by forward recoil spectrometry

ArticleinApplied Physics Letters 54(6):590 - 592 · March 1989with1 Read
Impact Factor: 3.30 · DOI: 10.1063/1.100888 · Source: IEEE Xplore

    Abstract

    A novel time‐of‐flight detector system for He<sup>+</sup> forward recoil spectrometry which improves the depth resolution to better than 35 nm has been used to investigate the form of the surface enrichment profile in a protonated (normal) polystyrene (PS)/deuterated polystyrene (d‐PS) blend. The volume fraction ϕ of d‐PS depends on the depth z as ϕ(z)=ϕ ∞ +(ϕ 1 -ϕ ∞ ) exp(-z/ξ), where ϕ 1 and ϕ ∞ are the surface and bulk volume fractions of d‐PS, respectively, and ξ is approximately the bulk correlation length, as predicted by theory.