High-frequency magneto-electrical properties of Zn1 − x − yAlxCoyO thin films

The Al doping effects on high-frequency magneto-electric properties of Zn1 − x − yAlxCoyO (x = 0–10.65 at.%) thin films were systematically studied. In the current work, the Zn1 − x − yAlxCoyO thin films were deposited by magnetron co-sputtering onto quartz substrates. The magneto-impedance spectra of the thin films were measured by an impedance analyzer. Among all the doped films studied, the thin film with 6.03 at.% Al-doping showed the highest ac conductivity and relaxation frequency. To characterize the relaxation mechanism underlying the magneto-electric properties, a Cole–Cole impedance model was applied to analyze the impedance spectra. The analyzed result showed that the magneto-impedance of the Zn1 − x − yAlxCoyO is contributed by multiple processes of magnetization dynamics and dielectric relaxation. The results imply that Zn1 − x − yAlxCoyO may be applicable for high-frequency magneto-electric devices.