
450 Engineering of Polymers and Chemical Complexity
FIGURE 44 Hexagonal pits in oxidized PRFL (10k x magnification)
When under developed pits are examined closely they are found to be free of
impurities and structured in the characteristic corkscrew manner expected for screw
dislocations, as shown in Figure 45.
FIGURE 45 Hexagonal pits on screw dislocation (30k x magnification)
No evidence could be found for the presence of any impurities in the PRFL sam-
ple. Overall, the PRFL graphite clearly demonstrates the expected behavior for highly