Structure and texture of pyrolytic graphites (PG) make it unlikely that the three dimensional electron-energy bands of ideal graphite would provide an adequate basis for a discussion of electron transport processes over a broad temperature range.1 We propose to demonstrate that a coherent description of PG layer-plane phenomena can be based on a parabolic two band system with cylindrical equal-energy surfaces, which are located around the vertical Brillouin zone edges. In this simple two-band model (STB model), band overlap and effective mass must be interpreted as phenomenological parameters to be derived from experiments on highly heat-treated pure PG; with p-type (boron doped) specimens, the objective is to describe the situation from the shift of the Fermi level, on the assumption that the presence of trapping centers would not inject major perturbations in the band structure.
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