Cryogenic dissipation-noise coupling in a Fe-based nanocrystalline soft magnetic alloy: A loss-separation framework with fluctuation analysis and domain-wall insights
Randomized trial reveals the temperature-dependent loss and noise dynamics in cryogenic soft magnets, implying device sensitivity limitations during cooldown.
Key Points
This research aims to explore the relationship between dissipation and noise in soft magnets at cryogenic temperatures.
Investigated a Fe-based nanocrystalline soft magnetic alloy using a reduced effective loss-separation model.
Applied the fluctuation-dissipation theorem to the temperature-dependent effective loss model.
Utilized Lorentz TEM observations to support domain-wall depinning mechanisms.
Model reproduces experimental losses with high fidelity (R² > 0.98).
Predicted a non-monotonic intrinsic magnetic-noise peak near 194 K.
Supported microscopic evidence for increased domain-wall-mediated effective dissipation.