SPIN-GLASS-LIKE BEHAVIOR IN CU/NI MULTILAYERED FILMS

A detailed magnetization study of Cu/Ni multilayered films made by sputtering is presented, and it is shown that these films are reentrant systems and not ordinary ferromagnets as often assumed. The transition from the spin-glass phase to the ferromagnetic phase is identified by the temperature Tp at which a peak in the dc magnetization occurs. This peak is seen in all the samples and Tp decreases as (bilayer thickness) decreases. The ferromagnetic region between Tp and the Curie temperature TC is also identified. © 1990 The American Physical Society.