Annealing effects on Py/Cu GMR multilayer films with limited number of sublayers

The influence of annealing on giant magnetoresistance (GMR) effect and magn etization reversal processes has been investigated in Py/Cu (Py = Ni83Fe17) sputter-deposited multilayers (MLs) with a limited number of magnetic subl ayers (N less than or equal to 6) and equal sublayer thicknesses both for P y and Cu (t(Cu) = 2 nm, t(Py) = 2 nm). Based on the magnetization and magne toresistance measurements it has been shown that the magnetic behavior of s uch MLs is strongly influenced by annealing driven disruption of magnetic l ayers (lateral decoupling) and nonmagnetic layers (magnetic bridging betwee n Py layers). A comparison of experimental hysteresis curves with model dep endences indicates that annealing causes a change of the magnetization reve rsal from a local to an absolute energy minimum mode leading to quasi-two-s tate magnetoresistance characteristics.