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arXiv · 2503.22623

Giant Spin Pumping at Polymer/Ferromagnet Interfaces for Hybrid Spintronic Devices

Shiva Gaur·Akash Kumar·Himanshu Bangar·Utkarsh Shashank·Hukum Singh·Saroj P. Dash·Anubhav Raghav·Johan Åkerman
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Abstract

While the growing utilization of polymers in flexible electronic devices has sparked significant interest in polymer/metal interfaces, spintronic studies of such interfaces remain limited. Here, we systematically study spin pumping across a polymer/ferromagnet metal interface between hydrogen silsesquioxane (HSQ) oligomer layers ($t_\mathit{HSQ} = 30, 36, 48$ nm) and NiFe ($t_\mathit{NiFe} = 4, 5, 7, 10$ nm) thin films. Using ferromagnetic resonance measurements, we observe strong spin pumping (large linewidth broadening) and a giant spin mixing conductance, reaching 19.8~${\rm nm^{-2}}$ for HSQ = 48 nm, \emph{i.e.}~comparable to that of heavy metals. Our results suggest efficient spin transfer across the HSQ/NiFe interface, possibly originating from a combination of spin and orbital pumping, and provide valuable insights for designing self-powered and flexible spintronic devices utilizing polymers in combination with ferromagnetic materials.

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Shiva Gaur, Akash Kumar, Himanshu Bangar, Utkarsh Shashank, Hukum Singh, Saroj P. Dash, Anubhav Raghav, Johan Åkerman. 2025-03-28. Giant Spin Pumping at Polymer/Ferromagnet Interfaces for Hybrid Spintronic Devices. https://arxiv.org/abs/2503.22623

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