Charge Transport and Magnetotransport Properties of Polyimide Irradiated by 80keV Co Ions

Charge transport properties of polyimide films implanted with 80keV Co ions at two different fluences (series I: 1.25×10¹⁷ ions/cm², series II: 1.75×10¹⁷ions/cm²) are studied in detail. For series I, the temperature dependence of surface resistivity fits Mott's equation very well. It is on the insulating side of the insulator-metal transition (IMT). However, for series II, the temperature dependence of surface resistivity is not in agreement with Mott's equation. It is on the metallic side of IMT. The magnetotransport properties of these two series are also studied. No significant magnetoresistive effect is observed for series I at both 5K and 300K. For series II, an obvious magnetoresistive effect is observed at 5K, while there is no magnetoresistive effect at 300K. Rutherford backscattering spectrometry (RBS) is applied to confirm the actual fluence for these two series.