STRUCTURE AND DIELECTRIC PROPERTIES OF A LAYERED COMPOSITE OF BARIUM TITANATE - BARIUM FERRITE
The paper presents the results of a study of the influence of a constant magnetic field on the dispersion of the complex permittivity of a layered composite (connectivity 2-2) based on barium titanate - barium ferrite. It is shown that in the manufacture of a magnetoelectric composite of barium titanate - barium ferrite with a connectivity of 2-2, a strong diffusion of iron appears into the barium titanate ceramic layer at the interface between the two materials. It was found that iron penetrates evenly, with random deviations, and no exponential decline as iron enters into barium titanate is observed. It has been established that a constant magnetic field does not affect the dielectric characteristics in an alternating electric field at frequencies above 1600 Hz. At lower frequencies, annealing in the paraelectric phase increases the resistance of the sample, and subsequent exposure to a constant magnetic field leads to its decrease. It was revealed that changing the type of connectivity of the magnetoelectric composite from 0-3 to 2-2 adds additional, smaller, resonance and antiresonance peaks in the study of piezoelectric properties by the resonance-antiresonance method. At the same time, the samples have sufficient values of the piezoelectric modulus for practical application (d31 > 40⋅10-12 C/N; d33 > 120⋅10-12 C/N).