Conditions for the Formation of a Polymeric Coating and the Magnetic Properties of Cobalt-Based Amorphous Alloys

Resumo

This paper presents the results of an investigation of the influence of the polymeric coating used in the course of the production of magnetic shields and conditions necessary for its formation on the distribution of magnetization and magnetic properties of amorphous soft magnetic ribbons made from AMAG-172 alloy (Co‒Ni–Fe–Cr–Mn–Si–B). Study was performed on samples with a nearly zero saturation magnetostriction. The coating was applied onto the ribbon in the 90–130°C temperature range after heat treatments in air, which formed a state with a positive saturation magnetostriction. This study has shown that the formation of a polymeric coating at temperatures of 110–130°C leads to a reduction in the volume of domains with the orthogonal magnetization because of the change in the sign of the saturation magnetostriction. The maximum magnetic permeability in the ribbon with a coating is decreased upon its formation in the entire temperature range; however, a certain increase is observed over time.