No abstract

During the preparation process of the glass-covered magnetic aInorphous wires, axial, radial, and azimuthal internal stresses are induced, determining their magnetic properties. We have proposed a calculation method of the internal stresses induced during the solidification of the metal and during the cooling from the solidification temperature to room temperature due to the difference between the thermal expansion coefficients of metal and glass. For Fe77 QSi7 5B]5 glass-covered amorphous wires we found internal stresses of about 10 Pa. The values and distribution of these stresses depend on the radius of the metal and on the thickness of the glass cover. The stress distribution coupled with the specific high positive magnetostriction leads to an easy axes distribution associated with a magnetic domain structure consisting of a cylindrical inner core with axial magnetization and a cylindrical outer shell with radial magnetization.The inner core leads to the appearance of a large Barkhausen jump at low axial fields. We have calculated the ratio M"/M, (the reduced remanence) as being of about 0.75 -0.80. Magnetic measurements performed on samples prepared by us confirm the existence of the large Barkhausen jump but with a reduced remanence of about 0.95 that suggests the existence of a supplementary axial tensile stress. The dependence of the reduced remanence on external tensile stresses for wires covered by glass and after the glass removal confirms the existence of the supplementary stress whose value was estimated as being of the order of 10 Pa.

Recognizing the importance of magnetic thin wires for science and technology, the 6th International Workshop on Magnetic Wires was held on 6–7 July 2010, in Bodrum, Turkey. A wide range of topics were addressed from technological problems of micro‐ and nanowire fabrication, to advanced physical effects and novel applications. Furthermore, critical discussions on the present state of knowledge and future trends arose during the Panel Session on microwires. In the present report, the main aspects addressed at the Discussion Panel and at workshop presentations are summarized with the aim to state the present and future perspectives on these wire systems. This report is focused upon four topics chosen for broad discussions at the Panel: Fabrication and processing, Magnetization reversal and Dynamics, High‐frequency properties, and Technological applications.

No abstract

No abstract