| Abstract [eng] |
Multiferroics are materials that have two or more ferroic properties - ferroelectricity, ferromagnetism, ferroelasticity. Due to the mechanical interaction of the grains, these properties are dependent on each other - for example: the material can be polarized by a magnetic field or magnetized by an electric one. This is the magnetoelectric effect. These materials have promising applications in devices such as magnetic field sensors, current sensors, energy harvesters, transducers, memory, spintronic logic, and microwave shielding materials. The purpose of this work is to determine the relationship between the sintering time of cobalt ferrite grains and the grain size, and the relationship between the sintering time and the Maxwell relaxation time and activation energy, and to determine how the magnetoelectric coefficient depends on the grain sizes. An electron microscope and X-ray diffractometry were used to characterize the grain size. The dielectric constant was measured in the temperature range of 150 - 500 K and in the frequency range of 20 Hz - 1 GHz. During the work, it was found that the materials produced are competitive with similar materials studied by other teams. It was found that as the BaTiO3 grains decrease, the dielectric constant also decreases, which corresponds to the literature. The sintering time of cobalt ferrite slightly affects the dependencies of the dielectric permitivity, but the magnetoelectric properties depend significantly on the sintering time of cobalt ferrite - especially in combination with 200 nm size barium titanate. |
