{HEAD ~ The difference} in the contact potential measured before and after heating provides {TAIL ~ an indication} of the mobile ion concentration in the oxide layer 
provides
{ HEAD ~ The difference } in the contact potential measured before and after heating provides { TAIL ~ an indication } of the mobile ion concentration in the oxide layer
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH