THE EXTRAORDINARY HALL-EFFECT OF PD CO MULTILAYERS/

The magnetoresistivity and Hall resistivity of Pd/Co multilayers have been investigated down to 4.2 K, focusing on the difference between sa mples with in-plane and perpendicular magnetization. At 4.2 K, a sign change of the extraordinary Hall coefficient as a function of Co thick ness is observed at similar to 2 Angstrom. For a Co layer thickness of 2 Angstrom, an anomaly is found in the temperature dependence of both resistivity and Hall coefficient near 250 K, suggesting a magnetic ph ase transition in an alloyed interface region.