INVESTIGATION OF THE PHASE FORMATION PROCESS DURING THE SYNTHESIS OF CERAMIC MATERIALS BASED ON MODIFIED YTTRIUM MANGANITE

Abstract

The aim of this work is to establish the nature and sequence of phase formation processes in the synthesis of ceramic materials based on yttrium manganite using different manganese oxides and structure modifiers. Differential scanning calorimetry, X-ray phase analysis, and scanning electron microscopy were used as research methods in the work. The physicochemical and electrophysical properties of the obtained samples were determined. Samples of modified yttrium manganite were obtained by solid-phase sintering of the initial components at various temperature-time parameters of heat treatment. The influence of Bi₂O₃, CoO and TeO₂ additives on the physicochemical and electrophysical properties of prototypes was studied. Regularities of the structure formation processes and phase composition of ceramic materials are established in relation to the composition of raw materials and the technological parameters of the synthesis of modified yttrium manganite. It has been established that the addition of oxides of the RO type contributes to a decrease in the degree of crystallization of the samples, as evidenced by a decrease in the intensity of the diffraction peaks of the crystalline phases. In this case, the qualitative composition of the phases practically does not change, but the proportion of the amorphous component in the structure of the material increases. Bi₂O₃ has the most effective modifying effect in the synthesis of yttrium manganite. Its addition into the composition of the raw mixture intensifies the process of formation of the yttrium manganite phase with a crystal size of 2–4 μm, which is confirmed by the results of DSC, XRD, and electron microscopy. The intensification of the crystallization process due to the addition of bismuth oxide is explained by the developed mechanism of liquid-phase sintering and the formation of a significant number of crystallization centers. The developed ceramic materials based on modified yttrium manganite have a set of electrophysical characteristics that make it possible to recommend them for the manufacture of various elements of electronic technology.