High-temperature X-ray diffraction study of anorthite-tialite materials

The structure of two mixtures of anorthite and tialite (10 mol-% tialite + 90 mol-% anorthite, 15 mol-% tialite +85 mol-% of anorthite) has been investigated using XRD at different temperatures in solid and liquid states. Such mixtures are used as refractory materials in the lining furnaces for metals with a high melting point. All measurements were carried out using a high-temperature vacuum chamber under a purified helium atmosphere. It has been found that the XRD patterns of the solid samples show reflections of various modifications of tialite and anorthite. Weak reflections of mullite can be identified at temperatures above 1000°C. A structural model of the investigated melts has been proposed based on nanocrystal clusters located in a disordered diffuse matrix. The environment of the disordered part of the matrix is formed by particles (atoms, atomic clusters) that do not participate in nanocrystal clusters.