Contrast inversion in TEM studies of poly(ferrocenylsilane)-block-poly(dimethylsiloxane) diblock copolymers

摘要

This paper describes an unusual contrast inversion phenomenon in TEM imaging of PFS-b-PDMS block copolymer bulk samples. It is clearly observed especially in samples that show a lamellar morphology that the contrast inversion is accompanied by a contraction of the PDMS, domains and an expansion of the Fe-rich domains. The location of the iron- and silicon-rich domains was monitored by EDX analysis. We infer that the contrast inversion was caused by electron beam radiation-induced damage to, and possible cross-linking of, PDMS chains. A simple way to selectively deposit metal on electron beam patterned polymer film was demonstrated.