the variable resistor is formed of a metal oxide showing an n type conductivity, and a work function of the second electrode is larger than {HEAD ~ a work function} of {TAIL ~ the first electrode} 
of
the variable resistor is formed of a metal oxide showing an n type conductivity , and a work function of the second electrode is larger than { HEAD ~ a work function } of { TAIL ~ the first electrode }
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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL