language: en

[Confidential: not for distribution. Submitted to IOP Publishing for peer review]

20 February 2010

Multipeak ferromagnetic resonance behaviour tailored by magnetoelastic coupling in FeSiB/CoNi layered microwires

J. Torrejón, G. A. Badini-Confalonieri and M. Vázquez
Institute for Materials Science, CSIC.
28049 Madrid. Spain
E-mail: jtorrejon@icmm.csic.es phone: 0034-913349000.

[Multipeak FMR_FeSiB/CoNi microwires]

[Page 2 of 15]

Abstract.-The aim of this work is to report on the influence of the presence of a magnetically hard layer with large thickness in the ferromagnetic resonance behaviour of soft/hard biphase microwires. Such microwires consist of FeSiB soft nucleus, intermediate glass layer and CoNi hard outer shell, and are prepared by combined quenching and drawing technique with electrochemical deposition. The unusual FMR response observed for this biphase system is characterised by the presence of a multipeak absorption spectrum that depends on the static field and on the thickness of the hard phase by means of magnetoelastic coupling. For thick enough CoNi layer, the internal stresses induced in the nucleus during electroplating process are very strong, giving rise to three electromagnetic absorptions: one at low frequency related to CoNi shell and two more at higher frequencies corresponding to the FeSiB nucleus which are ascribed to two well-defined magnetization regions with different magnetic anisotropy.

PACS: 75.60.Ch, 75.60.Ej, 75.60.JkNp KeyWords: Multipeak Ferromagnetic Resonance; Biphase magnetic microwires; Magnetoelastic coupling.

[Multipeak FMR_FeSiB/CoNi microwires]

[Page 3 of 15]

Introduction: on the FMR of magnetic microwires.-