Phase separation and crystallization in soda-lime borosilicate glass enriched in MoO3 studied by in situ Raman spectroscopy at high temperature

Magali Magnin , Sophie Schuller , Daniel Caurant (1) , Odile Majérus , Dominique de Ligny , Thierry Advocat

1 IRCP - Institut de Recherche de Chimie Paris

Phase separation and crystallisation processes may arise in molten glass when the MoO3 content exceeds its solubility limit. Molybdenum combined with other elements such as alkali and alkaline-earth may form crystalline molybdates, known as "yellow phases" in nuclear glasses. In order to establish the sequence of phase separation and crystallization processes occurring during the cooling of the melt, a non-radioactive simplified glass composition was chosen in the SiO2-B2O3Na2O-CaO system, with 2mol.% MoO3 . Various cooling scenarios were tested: cooling by air blowing, quenching between two copper plates and cooling on metallic plate. The resulting glass specimens were then characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy in temperature. These observations made it possible to determine the sequence and the appearance temperature of phenomena upon cooling: first, a phase separation occurs, (small droplets dispersed in the molten glass) followed by molybdates crystallization inside the droplets.

Mots clés: Glass; MoO3; Crystallization; CaMoO4; Na2MoO4; Raman at high temperature

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Magali Magnin, Sophie Schuller, Daniel Caurant, Odile Majérus, Dominique de Ligny, et al.. Phase separation and crystallization in soda-lime borosilicate glass enriched in MoO3 studied by in situ Raman spectroscopy at high temperature. 2008. ⟨hal-00994577⟩