Permeability Measurements on Amorphous and Annealed Samples of Fe_(73.5-x)Cr_xCu1Nb3Si_(13.5)B9 Alloys

摘要

Permeability and coercivity are the most important parameters for the evaluation of soft magnetic materials. The criteria for the softest magnetic materials demand very high permeability and / or extremely low coercivity and these properties necessitate the anisotropy energy and the magnetoelastic energy tend towards zero. These unique demands are fulfilled when the FINEMET type of nanocrystalline materials are thermally treated around there primary crystallization temperature which facilitates the evolution of nanometric size of the Fe(Si) grains (10-12 nm) that are exchanged couple through the remaining thin residual amorphous interface. In the present paper, it is tried to correlate the microstructural features with soft magnetic properties of the alloys, initial permeability of the toroidal shaped samples annealed at different temperatures are measured at room temperature with an applied ac field of 10~(-3) Oe.