| dc.description |
The effect of pressure (up to 15 kbar) and magnetic field (up to 8 T) on the low-temperature (down to 1.3 K) DC conductivity and magnetoconductance (MC) of ion-irradiated ( and ions) polyimide films with a room-temperature conductivity of 200 - 400 has been investigated. It was shown that for samples on the metal side of the metal - insulator transition with the resistivity ratio the application of pressure increases (300 K) by a factor of 2 - 3 with respect to that at ambient pressure and the value of is slightly reduced. The low-temperature conductivity shows a dependence. The sign of the MC at ambient pressure is negative at all fields, thus implying that the contribution for the electron - electron interaction is dominant. However, at 15 kbar a positive MC at low fields, in both the transverse and the longitudinal directions to the field, has been observed. This implies that under pressure the system is more metallic with respect to that at ambient pressure, and the positive MC due to the dominance of the weak-localization contribution is enhanced by making the system more metallic under pressure. |
