There is then a further heating and cooling stage in {HEAD ~ an oxidising atmosphere} which acts to remove {TAIL ~ intercalated carbon moieties} from the metallic feature 
acts to remove
There is then a further heating and cooling stage in { HEAD ~ an oxidising atmosphere } which acts to remove { TAIL ~ intercalated carbon moieties } from the metallic feature
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH