Frequency Response of a Coupled Magnetoelectric Hexaferrite Film on a Spiral Coil

This letter presents an experimental assessment and evaluation of the frequency response of a recently proposed magneto-electric (ME) device (suitable for H- and E -field sensor and tuning applications). The device is fabricated by incorporating a single-phase ME hexaferrite thin film on a silicon substrate, which is able to operate at a few volts. A conductive buffer layer of indium tin oxide is introduced between the Si substrate and the ME film to accommodate the voltage reduction for ME film excitation at room temperature. A planar spiral coil is then utilized for application or detection of an ac magnetic field by excitation of the ME film or change in magnetization as a flux, respectively. Through a nonlinear experiment, the frequency of the signals for both spiral coil and ME film is changed in the range of 1-10 MHz. The voltage across the coil is then measured as a function of the two sources with coupled frequencies. Coupling is, therefore, related to the frequency and amplitude of both these signals. The frequency response in these experiments provides a better understanding of the ME effect coupling. Experimental data confirm these findings.