Microscopic studies of oxidized highly oriented pyrolytic graphites

Journal Article · 16 April 2003 · Carbon

DOI: https://doi.org/10.1016/0008-6223(74)90069-4 · OSTI ID:4689180

Rodriguez-reinoso, F. ^[1]; Thrower, P. A. ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States)

Microscopic examination of two highly oriented pyrolytic graphites reacted with oxygen has revealed some unusual structural features. Oxygen attack occurs on basal plane surfaces to produce channels at crystallite boundaries, monolayer pits at lattice vacancies, and deeper pits at some unidentified structural defects. It is argued that these defects are not non-basal screw dislocations but may be associated with some structural irregularity which occurred during deposition. The depth of these pits (~ 10 μm) is much larger than the crystallite dimension, L, (~ 500Å). At the edge surfaces, where the majority of the oxidation occurs, preferential attack is evident from channels which appear to follow random paths into the material up to 120 μm long. Further, these are suggestive of catalytic attack but no catalyst particles have ever been observed. On some edge surfaces a blocky structure is observed which may be related to terraces in the basal plane pits. These observations indicate the presence of a structural macrounit containing several crystallites, highly oriented but separated by basal plane twist boundaries.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States)
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• NSA Number: NSA-26-007139
• OSTI ID: 4689180
• Alternate ID(s): OSTI ID: 4258739
• Report Number(s): NYO--1710-105; {"","Journal ID: ISSN 0008-6223"}
• Journal Information: Carbon, Journal Name: Carbon Journal Issue: 3 Vol. 12; ISSN 0008-6223
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English