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AM: Magnetismus
AM 5: Symposium: Sensorik
AM 5.2: Invited Talk
Monday, March 27, 2000, 14:30–15:00, H10
Thin Wires: Magnetization Process and Sensor Applications — •M. Vázquez — Instituto de Magnetismo Aplicado and Instituto de Ciencia de Materiales, P.O. Box 155, 28220 Las Rozas (Madrid), Spain
The study of the magnetic behaviour of thin wires is currently a topic
of growing interest due to their outstanding magnetic properties. This
behaviour firstly permits to consider them as nearly ideal specimens
for
basic research in micromagnetics and additionally make them suitable
for
applications as sensing elements in various technological devices. The
following families of wires are considered: i) Amorphous and
nanocrystalline wires and glass-coated microwires prepared by rapid
solidification into-rotating-water or by quenching and drawing,
respectively, and ii) Electrodeposited microtubes onto Cu wires and
nanowires filling porous membranes. Diameter of wires is in the range
from 100 nm up to 100 micron.
The magnetization process is discussed paying particular attention to
bistable wires where a single quite large Barkhausen jump is observed
between two stable remanence states.
Studies about the propagating wall during reversal and the
magnetostatic interactions among wires will be presented.
High frequency technically-oriented properties as giant
magnetoimpedance and ferromagnetic resonance are also discussed.
Finally, various sensor devices making use of the excellent properties
of the wires are introduced. Among others, encoded magnetic tags using
magnetic bistability as sensing principle,
current and position
sensors
based on the magnetoimpedance effect, and security fence and signature
authentication system based on the magnetoelastic properties.