Magnetoelectric thin film composites with interdigital electrodes

Abstract

Magnetoelectric (ME) thin film composites on silicon cantilevers are fabricated using Pb(Zr0.52Ti0.45)O3 (PZT) films with interdigital transducer electrodes on the top side and FeCoSiB amorphous magnetostrictive thin films on the backside. These composites without any direct interface between the piezoelectric and magnetostrictive phase are superior to conventional plate capacitor-type thin film ME composites. A limit of detection of 2.6 pT/Hz1/2 at the mechanical resonance is determined which corresponds to an improvement of a factor of approximately 2.8 compared to the best plate type sensor using AlN as the piezoelectric phase and even a factor of approximately 4 for a PZT plate capacitor.

Magneto-electric interactions at bending resonance in an asymmetric multiferroic composite: Theory and experiment on the influence of electrode position

“…4,10,15,[20][21][22] Sensitivities of a few pico-Tesla to hundreds of femto-Tesla for 1-30 Hz magnetic fields are required for such application. A viable approach for achieving such sensitivities is a bilayer ME sensor operating under frequency modulation at bending resonance.…”

“…9,10,20 A very high ME sensitivity was also reported under bending resonance in a cantilever of FeCoSiB and PZT with inter-digital electrodes. 21 …”

Tuning fork for noise suppression in magnetoelectric sensors

“…The Si wafers were diced into cantilevers with the dimension of 25 mm × 2 mm. The magnetostrictive phase was made of FeCoSiB and annealed according to [1]. The single sensors feature a capacitance of about 820 pF.…”

“…The PZT thin films with a composition at the morphotropic phase boundary were prepared by chemical solution deposition based on a 2-methoxyethanol route with pentane-2,4-dione as stabiliser. Further information on the preparation of the PZT and the ZrO 2 layers are described in [1]. Both PZT films have been designed with an interdigital transducer (IDT) structure (15 m spacing, 1.4 mm effective width (total width 1.8 mm), a total length of 10 mm, an electrode finger width of 15 m, and a thickness of 5 nm Cr adhesion layer and 100 nm Au).…”

“…The strain in the cantilever is transferred to a piezoelectric layer which is metalized with interdigital electrodes [1]. The strain leads to an electrical polarization or an electrical potential at the electrodes.…”