Effect of composite origin on magnetic properties of glass-coated microwires

• Observation of interfacial layer between the glass coating and metallic nucleus.
• Evaluation of the elements distribution within the glass coating and metallic nucleus.
• Discussions of the effect of interfacial layer on magnetic properties of microwires.
• Observation of gas bubbles within the glass coating with volume content of about 8–10%.
• Discussions of the effect of gas bubbles on the inhomogeneities in the internal stresses distribution.

We observed that magnetic properties (Giant magneto.-impedance effect and domain wall dynamic) of glass-coated microwires are closely related with the peculiarities of the fabrication technique involving rapid solidification of metallic alloy surrounded by glass coating from the melt.We present studies of the interfacial layer between the metallic nucleus and glass coating and studies of the inhomogeneities related with fabrication process of thin ferromagnetic microwires.We observed gas bubbles within the glass coating with volume content of about 8–12%. The sizes of the bubbles were between 1 and 15 μm. The existence of such bubbles might be the origin of the inhomogeneities in the internal stresses distribution.Using scanning electron microscope JEOL JSM-6610 we obtained the image of the interfacial layer and the elements distribution within the glass coating and metallic nucleus. This allowed us to estimate the thickness of the interfacial layer.Understanding of the origins of the interfacial layer and defects may help for improvement of the existing technology for thin composite wires fabrication and enhance their magnetic properties.