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Characterization of Softmagnetic Thin Layers using Barkhausen Noise Microscopy

Published online by Cambridge University Press:  21 March 2011

Jochen Hoffmann ,
Norbert Meyendorf  and
Iris Altpeter
Jochen Hoffmann
Affiliation:
Center for Materials Diagnostics, University of Dayton, Dayton, OH 45469-0121, U.S.A.
Norbert Meyendorf
Affiliation:
Center for Materials Diagnostics, University of Dayton, Dayton, OH 45469-0121, U.S.A.
Iris Altpeter
Affiliation:
Fraunhofer Institute for nondestructive Testing IZFP, Saarbruecken, Germany
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Abstract

Ferromagnetic materials are essential for data recording devices. For inductive or magnetoresistive (MR) sensors softmagnetic thin layer systems are used. Optimal performance of these layers requires homogeneous magnetic properties, especially a pronounced uniaxial magnetic anisotropy. Furthermore, microstructural imperfections and residual stresses influence the magnetic structure in the layer system.

Barkhausen Noise Microscopy enables the characterization of such thin layers. By cycling the magnetic hysteresis of ferromagnetic material electrical voltages (the Barkhausen noise) are induced in an inductive sensor. Miniaturization of the sensor and the scanning probe technique provides resolution down to few micrometers. Two materials were examined in terms of their structure, thickness, residual stresses and heat treatment condition: Sendust, used in inductive sensors and nanocrystalline NiFe, used in MR-sensors. In quality correlations to Barkhausen noise parameters were found. For representative sample a quantification of residual stress distribution could be established employing X-ray stress analysis.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 674: Symposia T/U/V – Applications of Ferromagnetic and Optical Materials, Storage and Magnetoelectronics , 2001 , U1.5
Copyright
Copyright © Materials Research Society 2001

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References

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