Conditions for the Occurrence of Spontaneous Oscillating Magnetic Relaxation in Synthetic Pt/Co/Ir/Co/Pt Ferrimagnets

It has been established that nonmonotonic magnetization relaxation in Pt/Co/Ir/Co/Pt synthetic ferrimagnets (SF) with perpendicular magnetic anisotropy is caused by the coincidence of two or three switching fields between stable states of the SF magnetization (double or triple point). The fields of switching between the stable states of SFs are determined by the ratio of the Zeeman energy, interlayer exchange energy, and the energies of magnetization reversal barriers of each layer, depending on the thickness of the layers and temperature. It has been shown that the selection of thickness and/or temperature enables reaching double and triple points at which the transition fields between the states coincide, which causes a nonmonotonic magnetic relaxation of SFs.