Effect of Au underlayers on GMR properties of NiFe/Cu/CoFe sandwiches

We have developed a new structure that has a GMR sandwich and one or two Au layers at the outer boundaries (Au/NiFe/Cu/CoFe/Au). This structure is designed to employ a specular reflection of conduction electrons from the Au layers. The potential advantages of this structure compared to multilayer films are low saturation field, high sheet resistance and the ability to use scissoring fields from a current for patterned narrow line structures, while maintaining a high GMR. All layers were deposited using rf diode sputtering. Coercivity difference between the two magnetic layers is used to realize the antiparallel alignments of the magnetizations of NiFe and CoFe layers. Comparing with similar structures without Au layers, the new structure has a GMR increase of 35% after discounting the shunting effect of the Au underlayers. Single layer Au films as thin as 40 /spl Aring/ have been made with a large specularity parameter when deposited on Bi/sub 2/O/sub 3/ and after annealing.