Synthesis and Structure of Ceramics of Bisubstituted M-Type Hexaferrite BaFe(11.5-x)Ti0.5AlxO19

The development of scientific and technological progress is impossible without the creation of new functional materials. One of the classes of such materials are hexagonal ferrites. Their unique physical properties make them an irreplaceable material for the production of high-frequency electronics. The widespread introduction of high-frequency electronics into everyday life, over the past decade, has generated great interest in hexagonal ferrites. The number of publications devoted to the synthesis of mono- and bisubstituted ferrites noticeably increases every year. Modification of the chemical composition of a ferrite by replacing some of the iron atoms with another element, without changing its structure, leads to a change in physical properties of the material. Variation of the final ferrite properties, by changing its chemical composition, is of interest and is promising for fine tuning the material properties for a specific task. The aim of the present work is to experimentally study the possibility of synthesizing ferrite with a magnetoplumbite structure, in which the iron atoms are partially replaced by the Al and Ti atoms. A review of the scientific literature on this issue showed the absence of publications on ferrites with such a set of substitute elements. The X-ray phase and structural analysis, electron microscopy, and energy-dispersive X-ray spectroscopy were used as research methods in the present study. The article offers the results of an experimental study of the possibility of obtaining bisubstituted M-type ferrite of the BaFe(11.5-x)Ti0.5AlxO19 composition, where x (Al) = 0.1, 0.5, 1. Solid-phase synthesis has been used as a method for preparing samples. This method is devoid of technological difficulties and is promising from the point of view of its scaling for the synthesis of ferrite. The samples have been sintered at three different temperatures: 1300, 1350, and 1400 °C. It is shown that in the temperature range 1300–1400 ° C the formation of monophase samples occurs. The calculation of the parameters of the crystal lattice has been made. The influence of temperature and concentration of a substituting element on the change in the parameters of the crystal lattice of the material has been revealed. The study by the electron microscopy method made it possible to reveal the presence of latent microporosity of the samples.