Correlation between MI Effect and Transverse Anisotropy in Stress‐Annealed Nanocrystalline Alloys: A Mössbauer Effect Study

In order to understand the correlation between the large and sensitive magneto-impedance (MI) effect in the tensile stress-annealed Fe-based nanocrystalline alloy Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 and the transverse magnetic anisotropy on a microscopic scale, a Mossbauer effect study has been carried out. A series of ribbon samples were subject to thermal annealing with tensile stress a up to 60 MPa. MI measurements showed that the effective field of transverse magnetic anisotropy H k increases with increasing σ. Analysis of Mossbauer spectra provided direct evidence that there is an increasing transverse magnetic structure with increasing σ in these tensile stress-annealed samples. This work confirms, on the microscopic scale, that the transverse magnetic anisotropy arises from stress-annealing and is essential for the giant magneto-impedance effect.