Mx. Wan et al., STRUCTURE AND ELECTRICAL AND MAGNETIC-PROPERTIES OF POLYIMIDE FILMS PYROLYZED AT HIGH-TEMPERATURE, Journal of applied polymer science, 61(5), 1996, pp. 793-798
Insulator-to-metal transition of polyimide films can be performed by p
yrolysis at high temperature as proposed by the authors. The maximum c
onductivity of the polyimide pyrolyzed at 950 degrees C for 0.5 h in a
nitrogen atmosphere was measured to be 248 S/cm. The structure, elect
rical, and magnetic properties of the pyrolyzed polyimide depend on th
e pyrolytic conditions, such as pyrolytic temperature and time. The py
rolysis process consists of carbonization and graphitization processes
, and a distinguishable pyrolytic temperature between them was estimat
ed to be about 700 degrees C. In the carbonization process, an increas
e in conductivity with the pyrolytic temperature may be due to the for
mation of localized charge carriers. In the graphitization process, on
the other hand, it is suggested that the delocalization of charge car
riers is responsible for the high conductivity observed from pyrolytic
temperature higher than 700 degrees C. (C) 1996 John Wiley & Sons, In
c.