Controlling the magnetization reversal mechanism in Co/Pd multilayers by underlayer processing

The effect of various process parameters on the magnetic properties of sputter deposited Co/Pd multilayered films is presented. The coercivity of the films was found to increase logarithmically with the thickness of the Pd underlayer. Various combinations of sputter gas (Ar) pressure during the deposition of the underlayer (Pul) and during the deposition of the multilayer (Pml) were studied. Coercivity was found to depend on both Pul and Pml. When Pml was kept constant at 3 m Torr, a decrease in coercivity with the increase in Pul was observed. And, for a constant Pul of 3 m Torr, an increase in coercivity was observed when Pml was increased. The magnetization reversal mechanism of these films was found to change from domain wall motion to rotation when Pul is increased from 3 m Torr to 18 m Torr or higher. However, the change in the reversal mechanism was not observed with the variation in the preparation conditions of the magnetic layer or the other underlayer process parameters such as the thickness or sputter power.