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

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 mu m. 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. (C) 2013 Elsevier Ltd. All rights reserved.