Didenko Y. Microwave absorption and thermal stability of dielectric materials

The thesis is devoted to the study of electric energy absorption mechanisms in the dielectric material to identify the dominant mechanism in the microwaves, and thermal stability dielectrics with a high dielectric constant. In microwave dielectrics with high permeability, the dominant mechanism of losses appears the polar phase presence. It is concluded that the level of losses in the composite materials is determined mainly by the properties of the matrix. The method of nonuniform microstrip resonator is developed that makes possible dielectric constant and dielectric loss tangent of material measurement with a reasonable accuracy. A review properties of existing thermostable dielectric materials with high permittivity and methods of obtaining them is given. It is shown, that the "hard paraelectric" doping by the paramagnetic rare earth elements ions, leads to the suppress of paraelectric non-stability of dielectric constant by paramagnetism.