Fabrication and characterization of shape anisotropy AlN/FeCoSiB magnetoelectric composite films

Abstract The shape anisotropy magnetoelectric (ME) composite films composed of piezoelectric AlN film and magnetostrictive FeCoSiB strips film were fabricated successfully by means of hard-mask during sputter deposition. The results demonstrated that the ME anisotropy factor K was strongly dependent on the number of FeCoSiB strips. If the number of strips is not more than eight, the ME anisotropy factor K increases slowly with increasing the strips' number. In addition, ME anisotropy factor K increases sharply when the number is more than eight. Furthermore, as the number of FeCoSiB strips increases to ten, the maximum ME anisotropy factor K reaches up to a value of 135, close to the theoretical value 175. However, by calculation, the ME anisotropy factor K will reach up to 11,357 if the FeCoSiB strips are prepared to possess the value of 1 μm in width by high precision photo-etching technology. In that case, the noise signal will be reduced to 5 nT. The shape anisotropy AlN/FeCoSiB ME composite films prepared in this work show great potential application in magnetic field detection in view of good ME anisotropy property.