Study of volt-ohmic characteristics of composites based on barium hexaferrite

To date, the task of creating new, previously unknown materials, which will have the characteristics demanded in practice, remains relevant. This article presents the results of the study of magnetic materials that are in great demand in modern technologies. One of the important characteristics of magnetic materials is electrical resistance. Since the electrical resistivity of magnetic materials mainly depends on their chemical composition, structure and method of preparation, the aim of the present study is to create a concentration range of composites and to study them, to select the preferred composition of materials based on barium hexaferrite for further study. This paper presents the results of the preparation and study of composite materials based on barium hexaferrite BaFe12O19, which is known for the diversity of its functional characteristics. Important among them is the high value of electrical resistivity. To study the properties of such materials, a series of samples maded by the method of two-stage solid-phase synthesis of barium hexaferrite with the addition of aluminum oxide Al2O3 and boron oxide B2O3 were prepared. The first stage is the synthesis of barium hexaferrite BaFe12O19 from barium carbonate BaCO3 and iron oxide Fe2O3 (homogenization, compaction, sintering, grinding, powder classification). The second stage is the production of composite materials from powders of barium hexaferrite BaFe12O19, oxides of boron B2O3 or aluminum Al2O3 (homogenization, compaction, sintering). The addition of aluminum oxide Al2O3 and boron B2O3, according to the authors, is capable of varying the properties of the composite over a wide range due to the difference in magnetic susceptibility and the dielectric constant of its components. To measure the electrical resistance of the synthesized samples, the MIC-2500 device was used in a DC voltage range of 50-2500 V. In this work, the dependences of the specific resistance on the concentration of oxides are plotted. The optimal compositions with the best values of resistivity for the composites under study were determined.