{HEAD ~ The intermediate layer} is mainly composed of {TAIL ~ Ru}, Si, Ge or carbon, or is a mixed layer including Ru, Si, or Ge mixed with at least one of carbon, nitrogen or oxygen, with a composition gradient across its thickness 
is mainly composed of
{ HEAD ~ The intermediate layer } is mainly composed of { TAIL ~ Ru } , Si , Ge or carbon , or is a mixed layer including Ru , Si , or Ge mixed with at least one of carbon , nitrogen or oxygen , with a composition gradient across its thickness
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH