Magnetoelectric effect in trilayered gradient composites LiNbO3/Ni/Metglas

In this work the effect of annealing in a constant magnetic field on the magnetoelectric (ME) coefficient in three-layered gradient composites is investigated. A technique of nickel electrochemical deposition on bidomain lithium niobate crystals was demonstrated. It is shown that the optimum temperature for the formation of the maximum remanent magnetization of the Ni layer in a constant magnetic field is 350 °C. In the samples annealed at this temperature, the maximum shift of the dependence of the ME coefficient on the external constant magnetic field relative to the value of 0 Oe was achieved. Quasistatic ME coefficient value was 1.2 V/(cm∙Oe) without applying of external DC magnetic field. The maximum value of the ME coefficient was reached 199.3 V/(cm∙Oe) at bending resonance of 278 Hz without external DC magnetic field. Obtained in this work values of ME coefficients don’t yield to most of ME composite materials which were published before.