The magnetoelectric (ME) composite is composed of magnetostrictive and
piezoelectric materials, which utilizes the response of each constituent under
the influence of the magnetic field and electric field. An electrical voltage can
be generated form the ME composite under magnetic field or vice versa due
to the interfacial coupling between magnetostrictive and piezoelectric
materials. This interfacial coupling of ME composites is defined by the ME
coupling coefficient which is crucial for determining the usage of ME
composites in various applications such as current sensor, tunable inductors,
energy harvesters, DC and AC magnetic field sensors, etc. Therefore, in order
to obtain the high-performance ME composites with high ME coupling
coefficient, it is necessary to select materials with excellent magnetostrictive,
piezoelectric coefficients and optimized interfacial bonding. Thus, the ME
composites were fabricated using Metglas with high magnetostriction and
face-shear 36-mode PMN-PZT single crystal with high piezoelectric
properties. As a result, the ME characteristic value of the 36-mode has a high
ME coupling which is approximately 90% similar to the 32-mode in off
resonance and resonance conditions. Moreover, the magnetic field sensitivity
of 36-mode has very high sensitivity which can detect the magnetic field up to
2pT at resonance condition. The resonance sensitivity of 36-mode ME
composite is comparable to costly and bulky magnetic field sensor such as
search coil sensor. In addition, a prototype DC magnetic field sensor was
fabricated using the face-shear 36-mode ME composite with high sensitivity.
The drive of the fabricated prototype DC magnetic field sensor in the DC
magnetic field was confirmed, which has a huge potential for the fixed-
frequency magnetic field sensor applications.
In addition, changed the magnetostrictive material to Ni showed similar
behavior with Metglas under off-resonance and resonance conditions.
However, the magnetoelectric characteristic value was found to be lower than
Metglas. Magnetic field detection limits were also much lower. However,
when compared with the magnetic field sensitivity of the conventional high
performance magnetic field sensors, it has been confirmed that it has a
similarly good magnetic field detection limit.