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Negative temperature coefficient of Gilbert damping in magnetic bilayers
Phys. Rev. B 113, L220409 – Published 22 June, 2026
DOI: https://doi.org/10.1103/qc2z-thq5
Abstract
The Gilbert damping of magnetic materials is an important magnetic parameter that determines the switching speed and energy dissipation of spintronic devices. In simple metals, the intrinsic Gilbert damping increases with temperature and diverges near the Curie temperature as a result of spin fluctuations. Here we present atomistic simulations and experimental measurements showing surprising and opposite behavior in Py/Nd bilayers, where the Gilbert damping decreases with increasing temperature. The effect arises because of the enhanced damping at the interface as a result of spin pumping, where elevated temperatures cause a dynamic separation of the interfacial and bulk magnetization during relaxation. Furthermore, the temperature dependence of the damping can be controlled by varying the thickness of the Nd capping layer. Our findings present a spintronic effect that can be used to modify the dynamic properties of nanoscale materials and devices for enhanced energy efficiency or with improved switching dynamics.
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- vampire software package v9, 2025, https://vampire.york.ac.uk/.
- The data supporting this research is openly available from the research data repository of the University of York at https://doi.org/10.15124/254bf8a1-42c7-4ea0-ba57-aa35ff9e5928.