Investigation on the electric and magnetoelectric properties of BaSrCo₂Fe_11.5Ga_0.5O₂₂ ferrite

The electric properties affected by the applying magnetic field or vice versa are known as magnetoelectric effect (ME effect), which caused great concern in recent years. Here, we reported the electric, magnetic and magnetoelectric properties of polycrystalline Y-type hexaferrite BaSrCo₂Fe_11.5Ga_0.5O₂₂. In particular, the frequency and temperature dependence of impedance, electric modulus, and ac conductivity, were studied. Grain and grain boundary effects were coexistent at low temperature of this sample, while at high temperature grain boundary effect was dominated. In addition, the universal power law (UPL) and superlinear power law (SLPL) regions were coexistent at low temperature. The magnetic transition temperature from helimagnetism to ferromagnetism was found at around 200 K. The magnetoelectric (ME) effect has been detected in the sample, and the ferroelectric polarization is induced by the magnetic field. What is more, the polarization can be reversed as the magnetic field changes signs. These results show that this ferrite is a good candidate for high temperature multiferroic applications and is also a good prototype for studying the SLPL mechanism in inorganic materials.