Olivine-MgO interfaces produced by crystallization of glass fulms on single-crystal MgO substrates

Abstract

Glassy silicates are present at grain boundaries in almost all liquid-phase sintered ceramic oxides. In many cases, the amorphous-crystalline interfaces in the sintered microstructure can be modified by inducing crystallization of the glassy phase. The intergranular phases in polycrystalline MgO are typically silicates with cations of calcium, magnesium and iron in the silicate network. A systematic approach to study the crystallization behavior of glass-MgO interfaces has been attempted in the present study. Following the work by Mallamaci in which crystallization of a silicate glass in contact with A12O3 was studied, devitrification of glass in contact with single-crystal MgO has been investigated. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to characterize the resulting microstructures.A pellet of Mg2SiO4 (forsterite) prepared by hot-pressing MgO and SiO2 powders was used as the target for depositing glass films onto single-crystal MgO substrates by pulsed-laser deposition (PLD). Glass films with the composition of olivine.