Phenomenological theory of the giant magnetoimpedance of composite wires
1 Institute of Experimental Physics, Saarland University - P.O. Box 151150, D-66041 Saarbruecken, Germany, EU
2 Department of Physics, East China Normal University - 3663 Zhongshan North Road, 200062 Shanghai, PRC
Received: 25 October 2012
Accepted: 18 December 2012
Composite wires with a three-layered structure are known to show a particularly large magnetoimpedance effect. The wires consist of a highly conductive core, an insulating layer and an outer ferromagnetic shell. In order to understand the origin of the effect, a theory based on a coupling of the Maxwell equations to the Landau-Lifschitz-Gilbert equation is suggested. The theory is phenomenological in the sense that it does not account for a domain structure. However, theoretical results nicely reproduce those obtained in various measurements. Furthermore, an upper limit of the magnetoimpedance ratio for a given combination of materials can be determined.
PACS: 75.47.-m – Magnetotransport phenomena; materials for magnetotransport / 75.70.-i – Magnetic properties of thin films, surfaces, and interfaces / 75.20.En – Metals and alloys
© EPLA, 2013