Anomalous depth distribution of Fe and Co atoms in polyimide implanted to high fluence

Abstract Polyimide foils were implanted with 40 keV Fe + and Co + ions to the fluences of 2.5×10 16 –1.25×10 17 cm −2 at ion current densities of 4, 8 and 12 μA/cm 2 . Structural and composition alterations of the implanted polymer are studied using transmission electron microscopy and Rutherford back-scattering methods. Ion implantation results in formation of the near-surface carbonaceous layer filled up to 25 at.% of the embedded metal. Anomalous depth profiles of the metals, consisting of a strong near-surface peak and two weaker ones beyond the implanted layer, are observed. Possible mechanisms of the metal redistribution are discussed.