The mechanism of the crystalline characteristics of spinel-induced epitaxial growth of diopside in CMAS glass-ceramics

The edge-to-edge matching model (E2EM) is used to predict and analyze the epitaxial growth mechanism of spinel and diopside in CaO-MgO-Al2O3-SiO2 (CMAS) glass-ceramics. At the same time, the prepared glass-ceramics were characterized by X-ray diffraction (XRD) and electron backscatter diffraction (EBSD). It is found that the theoretically predicted phase interface where epitaxial growth can occur is consistent with the conclusion measured by characterization. In the crystallization zone: < 1-12 >spinel//<001>diopside (1-11-)spinel at an angle 1.06° (200)diopside, < 1-12 >spinel//<101>diopside (311)spinel at an angle 1.26° (1- 31)diopside. Through models and experiments, it was found that spinel with a lattice constant of 7.632–8.597 Å (Fd-3 m) can provide a special nucleation interface for diopside, which can effectively induce the precipitation of diopside. This study provides good theoretical guidance for the preparation of diopside. Meanwhile, the model has strong potential to be used to develop new crystal nucleating agents in glass-ceramics.