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Lecture

Thin Film Magnetoelectric Composites for Magnetic Field Measurements

Thursday (08.06.2017)
10:50 - 11:10 Förde II
Part of:


In this presentation composite magnetoelectrics (ME) implemented as thin film systems are discussed in terms of their applicability as highly sensitive magnetic field sensors. Composite materials benefit from the advantage that their constituting phases can be optimized almost independently. Here, pulsed DC sputter deposited AlN serves as the piezoelectric component. The magnetostrictive phase is based on (Fe90Co10)78Si12B10 layers grown by magnetron sputter deposition. All functional layers are deposited with thicknesses of a few micrometers on Si cantilever structures with typical lateral dimensions of 1 mm x 3 mm and 3 mm x 25 mm.


To improve the minimum detectable magnetic field one could either increase the sensitivity given by the ME coefficient or reduce the sensor system noise governed by dielectric losses, irregular magnetization changes, acoustic interference and noise of the read-out electronics. For the cantilever design the highest sensitivities are observed for external magnetic fields with excitation frequencies matching the mechanical resonance frequency. Under such a condition, ME coefficients as large as 6900 V/cmOe and a limit of detection (LoD) below 1 pT/Hz1/2 can be measured. Our best result to date is a LoD = 500 fT/Hz1/2 at a frequency of 958 Hz using a set of two sensors for noise suppression.


Different measures such as frequency conversion techniques and the use of magnetostrictive multilayers are discussed in consideration of signal frequency range and noise level.

 

Speaker:
Dr. Dirk Meyners
Kiel University (CAU)
Additional Authors:
  • Volker Röbisch
    Christian-Albrechts-Universität zu Kiel
  • Onur Urs
    Christian-Albrechts-Universität zu Kiel
  • Matic Klug
    Christian-Albrechts-Universität zu Kiel
  • Sebastian Salzer
    Christian-Albrechts-Universität zu Kiel
  • Jens Reermann
    Christian-Albrechts-Universität zu Kiel
  • Erdem Yarar
    Christian-Albrechts-Universität zu Kiel
  • Christine Kirchhof
    Christian-Albrechts-Universität zu Kiel
  • Rahel Kruppe
    Christian-Albrechts-Universität zu Kiel
  • Dr. André Piorra
    Christian-Albrechts-Universität zu Kiel
  • Prof. Michael Höft
    Christian-Albrechts-Universität zu Kiel
  • Prof. Gerhard Schmidt
    Christian-Albrechts-Universität zu Kiel
  • Prof. Jeffrey McCord
    Christian-Albrechts-Universität zu Kiel
  • Prof. Dr. Eckhard Quandt
    Christian-Albrechts-Universität zu Kiel