Open AccessПолиморфизм ScBO-=SUB=-3-=/SUB=- при твердофазном синтезе из аморфных прекурсоров
Author(s) -
И.М. Шмытько
Publication year - 2019
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2019.11.48431.482
Subject(s) - annealing (glass) , crystallography , calcite , amorphous solid , isothermal process , materials science , atmospheric temperature range , trigonal crystal system , crystal structure , mineralogy , chemistry , thermodynamics , physics , metallurgy
Detailed X-ray studies of changes in the structure of ScBO3 in the process of successive isothermal annealing of the initial amorphous precursor were carried out. It was shown that, during successive annealing of an amorphous precursor, the crystalline phase is first formed at an annealing temperature of 710 ° C, the positions of the reflections of which do not coincide with the position of the reflections of the known calcite structure. This phase exists in a very narrow temperature range (~ 30 ° C) and with an increase in the annealing temperature to 750 ° C, it completely transforms into the known rhombohedral phase of calcite. Using the ENDEAVOUR software complex, the cell parameters, the positions of the atoms in the cell, and the space group of the symmetry of the new phase were determined. It turned out that the new phase corresponds to the hexagonal structure of vaterite (S.G. P63 / mmc), known for other rare-earth orthoborates (REM).