Spin-glass-like behavior in Cu/Ni multilayered films

Abstract

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 ${\mathit{T}}_{\mathit{p}}$ at which a peak in the dc magnetization occurs. This peak is seen in all the samples and ${\mathit{T}}_{\mathit{p}}$ decreases as \ensuremath{\lambda} (bilayer thickness) decreases. The ferromagnetic region between ${\mathit{T}}_{\mathit{p}}$ and the Curie temperature ${\mathit{T}}_{\mathit{C}}$ is also identified.