• • TSA induces a sharp increase in uniaxial anisotropy constant (Ku) from 22.5 to 665 J/m3 across 0–300 MPa stress, while maintaining ultrafine grain size (≤11 nm), enabling precise tuning of magnetic anisotropy without compromising nanocrystalline structure.
• • Domain width is refined from 110 to 36 μm with increasing stress, shifting magnetization mechanism from domain-wall displacement to rotation-dominated reversal, which is critical for achieving stable permeability at high frequencies.
• • At 50 MPa, effective permeability (μe) of ~2330 is maintained up to 1 MHz, while at 300 MPa, μe of ~585 remains constant from 1 kHz to 10 MHz, demonstrating exceptional frequency stability for MHz-class power electronics.
• • The quantitative correlation between Ku, domain structure, and μe provides a design framework for optimizing stress-annealing parameters to meet specific high-frequency application requirements, such as precision current transformers and EMC filters.