In-phase and out-of-phase spin pumping effects in Py/Ru/Py synthetic antiferromagnetic structures

The spin pumping effect in magnetic heterostructures and multilayers is a highly effective method for the generation and transmission of spin currents. In the increasingly prominent synthetic antiferromagnetic structures, the two ferromagnetic layers demonstrate in-phase and out-of-phase states, corresponding to acoustic and optical precession modes. Within this context, our study explores the spin pumping effect in Py/Ru/Py synthetic antiferromagnetic structures across different modes. The heightened magnetic damping resulting from the spin pumping effect in the in-phase state initially decreases with increasing Py thickness before stabilizing. Conversely, in the out-of-phase state, the amplified damping exceeds that of the in-phase state, suggesting a greater spin relaxation within this configuration, which demonstrates sensitivity to alterations in static exchange interactions. These findings contribute to advancing the application of synthetic antiferromagnetic structures in magnonic devices.