MAGNETORESISTIVE REMANENCE CURVES IN CO CU MULTILAYERS/

We report measurements of magnetoresistive remanence curves and initia l magnetoresistance curves on Co/Cu multilayers. The initial magnetore sistance curve shows an enhanced magnetoresistance change over that of the hysteretic magnetoresistance curve. Using remanence curves we are able to separate out the irreversible and reversible components contr ibuting to the magnetoresistance. We show that it is irreversible chan ges of resistance within the multilayers from an initial low energy de magnetised state that is responsible for this 'extra' magnetoresistanc e.