Radio-Absorbing Properties of Composites Based on Barium Titanate and Strontium Hexaferrite Component

The dielectric properties of synthesized composites, consisting of two components (the multiferroic SrFe 12 O 19 and the ferroelectric BaTiO 3 ), exhibiting combined magnetic and ferroelectric properties, have been investigated. A phase transition is shown to occur at Tc = 135 ℃, the degree of broadening of which increases with increasing concentration of strontium hexaferrite. For composites with barium titanate concentrations of x=75 and 80%, the greatest microwave energy absorption of a resonant type was observed, reaching 25-30 dB at spectral maxima. It was revealed that the frequency of the absorption spectrum's maximum can be manipulated through variations in sample temperature, uniaxial pressure, and the induction of a constant magnetic field. The largest frequency shift of the energy absorption peak (a decrease of 1.8 GHz or ~22%) is observed when the temperature is increased from 80 to 160 ℃. The features of absorption spectra of composites are interpreted from the point of view of resonance behavior of elements of domain structure of ferroelectrics and multiferroics in electromagnetic field.