  Palladium-iron alloys produced by high-dose implantation of iron ions into
epitaxial palladium films were investigated with the ferromagnetic resonance
(FMR) and vibrating sample magnetometry (VSM) techniques. The samples reveal
distinct multiple FMR responses depending on the dose of iron ion implantation.
The post-implantation annealing at 770 K does not bring the implanted films to
a homogeneous solid solution state, as might be expected from the Pd-Fe phase
diagram. On the contrary, the system approaches a stable state composed of
several magnetic phases. FMR spectra exhibit an angular behavior specific for a
stack of interacting magnetic layers. This observation, correlated with the
magnetometry data, indicates that the palladium-iron binary alloy has a
previously unknown tendency towards spinodal decomposition into isostructural
phases with well-defined iron concentrations and, accordingly, with different
temperatures of ferromagnetic ordering and saturation magnetizations.
